Factors Affecting Initial Enrollment Intensity: Part-Time versus Full-Time Enrollment

Transcription

1 acors Affecing Iniial Enrollmen Inensiy: ar-time versus ull-time Enrollmen By Leslie S. Sraon Associae rofessor Dennis M. O Toole Associae rofessor James N. Wezel rofessor Deparmen of Economics Virginia Commonwealh Universiy 1015 loyd Ave..O. Box Richmond, VA Corresponding Auhor: James N. Wezel [email protected] (804) AX: (804) June 2003 A preliminary version of his aper was presened a he 2001 AIR orum in Long Beach, CA. This maerial is based upon work suppored in par by he Associaion for Insiuional Research, he Naional Cener for Educaion Saisics, and he Naional Science oundaion under he Associaion for Insiuional Research 1999 Improving Insiuional Research in ossecondary Educaional Insiuions Gran rogram. The Spencer oundaion Small Grans program also provided funding. Leslie Sraon graefully acknowledges addiional suppor from a 2001 aculy Excellence Award from Virginia Commonwealh Universiy. Any opinions, findings, conclusions, or recommendaions expressed in his maerial are hose of he auhors and do no necessarily reflec he views of he Spencer oundaion, he Associaion for Insiuional Research, he Naional Cener for Educaion Saisics, or he Naional Science oundaion.

2 acors Affecing Iniial Enrollmen Inensiy: ar-time versus ull-time Enrollmen May 2003 ABSTRACT We develop a model derived from human capial heory ha explicily recognizes he role of opporuniy coss, paricularly employmen opporuniies, in deermining full-ime/par-ime enrollmen paerns for college sudens. Using naional daa from he 1990/94 Beginning os- Secondary Survey, we es his model by comparing hose iniially enrolled par-ime wih hose iniially enrolled full-ime. Empirical resuls are consisen wih he concepual model, indicaing ha, coningen upon he decision o aend college, individuals who are older or live in saes wih lower unemploymen raes are significanly more likely o enroll par-ime. JEL Codes: I21, J24 KEYWORDS: Demand for Schooling, Human Capial. 1

3 Inroducion The sereoypical college suden is an 18-year-old pursuing a full-ime course load. The realiy is ha abou fory percen of undergraduaes enrolled in degree-graning insiuions are aending on a par-ime basis 1. Many of hose enrolled par-ime are over he age of weny-four and/or employed. However, relaively lile is known abou he facors associaed wih enrollmen inensiy: he decision o enroll par-ime versus full-ime. We begin o address his gap in he lieraure by examining he decision o enroll iniially as a par-ime raher han a full-ime suden, coningen upon he decision o enroll. We call his decision he enrollmen inensiy decision. Our firs sep is o develop a concepual model based on human capial heory ha disinguishes beween par-ime and full-ime enrollmen. The driving force in his model is he opporuniy cos of ime and how ha cos differs as a funcion of enrollmen saus. This model predics ha older individuals because of heir greaer curren opporuniy cos of ime will be more likely o enroll par-ime han younger individuals even hough older individuals have less ime o reap he pos-graduaion economic rewards. We hen proceed o empirically evaluae his concepual framework using a probi model of firs erm enrollmen inensiy (par-ime versus full-ime), condiional upon having decided o enroll. The empirical evaluaion uses individual level daa from he Beginning os-secondary survey conduced by he Naional Cener for Educaion Saisics. This daa se conains informaion on personal and household characerisics for a naional sample of sudens who firs enrolled during he academic year. Informaion on labor marke condiions is merged wih hese daa in order o proxy for employmen-based opporuniy coss. We find ha hese 1 The Diges of Educaion Saisics, 2001 repored ha in % of he undergraduae 2

4 opporuniy coss significanly influence he enrollmen inensiy decision. or example, he higher he unemploymen rae he more likely one is o enroll full-ime since he probabiliy of finding a good job is lower. Lieraure Review There have been a large number of insiuion-specific enrollmen sudies (Ehrenberg and Sherman, 1984; Seneca and Taussig, 1987; Dickey, Asher, and Tweddale, 1989; and Moore, Sudenmund, and Slobko, 1991, o name a few). Those focusing on he Universiy of Minnesoa (Hoenack and Weiler, 1975, 1979; and Hoenack and ierro, 1990) are paricularly valuable because of he deailed daa used and he developmen of he analysis over ime. Sill, for a number of reasons, hese sudies shed lile ligh on he enrollmen inensiy decision. irs, many insiuion-specific sudies focus on radiional, residenial colleges where he ypical freshman is an year old, recen high school graduae, who enrolls full-ime 2. I is no clear how well he resuls of such sudies will generalize o commuer oriened schools in urban areas or o he naional level. Second, insiuion-specific sudies virually preclude he use of economic facors as deerminans of enrollmen saus, hus imposing limis on he specificaions ha can be esed. Variaion in expeced employmen probabiliies as well as expeced earnings is relaively small wihin a narrowly defined geographic area over a shor period of ime 3. This is paricularly rue when he suden body a he insiuion is relaively homogeneous or when he suden populaion aending degree-graning insiuions were enrolled par-ime. 2 One of he few aricles o focus on enrollmen decisions in a nonradiional sample is Sefor and Turner (2002), who examine he impac of ell Grans on he decision o enroll among older sudens using difference-in-differences esimaion on daa from he Curren opulaion Survey. They do no, however, disinguish beween par-ime and full-ime enrollmen. 3 In his review of he lieraure, W. Becker (1990) discusses he use of labor marke condiions in ime-series analysis of he demand for educaion and poins ou how difficul conrolling for such 3

5 sample is resriced o or consiss mainly of recen high school graduaes, as is ofen he case. Third, hese sudies do no ypically disinguish beween par-ime and full-ime enrollmen, even hough he fracion of firs-erm, degree-seeking undergraduaes aending par-ime is subsanial: 21.6% in By conras, use of a naional daa se avoids mos of hese problems. The more diverse suden populaion presen yields resuls ha are more represenaive of he populaion as a whole. Racial, ehnic, and geographic differences can also be exploied o idenify differences in employmen opporuniies. A number of researchers have used naional daa ses such as he Naional Longiudinal Surveys [NLS] (Borus and Carpener, 1984; Cabrera, Sampen, and Hansen, 1990), he High School and Beyond [HS&B] (Zucker and Dawson, 2001), or he Curren opulaion Survey [CS] (Corman, 1983; Mcherson and Schapiro, 1991) o examine he enrollmen decision. One of he relaively few sudies o conrol for economic facors is Ligh (1996). She uses daa from he NLS Youh cohor on individuals who began bu hen lef college, o esimae a hazard model of he decision o reurn o college a a laer ime and relaes ha o wages and he unemploymen rae. She finds ha he probabiliy of reenering falls as uiion raes and wage raes rise, and as he unemploymen rae falls. However, Ligh does no consider he iniial enrollmen decision nor (like mos researchers) does she differeniae beween full-ime and par-ime enrollmen. Indeed, many of he naional daa ses used o examine enrollmen consis of age-specific populaions so ha he age of he respondens is ypically quie young. Since mos of hose enrolled par-ime are older, he number of par-ime sudens from age-resriced daa ses may be oo small o draw any conclusions. In par as a response o hese daa issues and in addiion o facors can be in cross-secion analysis. 4

6 provide daa useful for longiudinal research effors, he Naional Cener for Educaional Saisics [NCES] has developed a number of naional longiudinal daa ses ha look a he populaion of college sudens, unresriced geographically or by age. These samples ypically conain far more non-radiional sudens. Recognizing he lack of research on older or par-ime sudens, a number of researchers have begun looking a hese non-radiional suden populaions, ofen using NCES daa. Bean and Mezner (1985) presen a summary of he relevan lieraure on nonradiional sudens and develop a concepual model of ariion for his populaion in which home and employmen consideraions play a significan role. In laer work (Mezner and Bean, 1987), hey repor empirical resuls supporing his model. Disseraions by Tynes (1993) and Sarkey (1994) examine he characerisics of older and par-ime sudens respecively. lacing par-ime sudens ino he same pool as full-ime sudens may influence he empirical resuls if hese differen suden populaions reac differenly o causal facors affecing enrollmen decisions. Thus, researchers have jusified analyzing only full-ime sudens. Ohers, like Horn (1998 U.S. Deparmen of Educaion), look a par-ime enrollmen as a risk facor driving ariion raher han as a decision iself. We model par-ime enrollmen as a choice and recognize ha differen suden populaions may be more or less likely o make ha choice. The Concepual Model Our approach o modeling enrollmen derives from human capial heory (G. Becker, 1975). According o human capial heory, individuals inves in human capial oday, if he cos of acquiring ha human capial is a leas covered by he discouned value of he expeced fuure 4 These saisics are drawn from he Diges of Educaional Saisics,

7 benefis. The cos consiss of boh direc uiion coss and foregone earnings, wih foregone earnings being he primary componen. The benefis arrive in he form of higher fuure paychecks. In he sandard model of he college enrollmen decision, an individual eiher enrolls in college or works and canno do boh. Thus, college enrollmen is viewed as a full-ime commimen o human capial formaion. Saisics indicae, however, ha many of hose enrolled in college are simulaneously employed and ha employmen saus is highly correlaed wih enrollmen saus. Daa from he Ocober 2000 CS indicae ha 15.7% of hose enrolled in college full-ime were employed fullime, 37.8% were employed par-ime, and 46.5% were no employed a all. The comparable measures for hose enrolled in college par-ime were 70.5%, 15.7%, and 13.8%. 5 Thus, seveny percen of par-ime sudens hold a full-ime job while more han eighy percen of full-ime sudens eiher do no work or work par-ime. This finding suggess a link beween employmen and enrollmen inensiy. Hence in his work, we exend he sandard human capial model o consider he enrollmen inensiy decision or he decision o enroll on a par-ime raher han full-ime basis. This exension requires explicily considering how he coss and benefis o enrollmen differ by enrollmen inensiy. Consider equaions 1 and 2: (1) NV College = G HS T C C + γ W G 1 + = 0 = G ( 1+ r) W ( γ, G ) ( r) 5 These saisics are available a hp:// 148/ab11.x. 6

8 (2) NV College = W G HS T C C + γ W G 1 + ( ) = 0 1+ r = G ( γ, G ) ( r) where C represens he direc coss associaed wih college, W HS reflecs he expeced earnings of an unenrolled high school graduae, W C reflecs he expeced earnings of a college graduae, γ is a muliplier ha reflecs he fracion of earnings (0 γ 1) an enrolled individual can expec o receive relaive o he earnings of one who is no enrolled bu is acively engaged in he labor force, G is he ime i akes o complee he college degree, o graduae, T is he ime ill he individual reires, and are superscrips ha refer o full-ime and par-ime enrollmen respecively, is a subscrip ha reflecs ime, and r is he discoun rae. Many of he variables are a funcion of enrollmen inensiy and/or ime. Thus, he direc coss associaed wih college (uiion, fees, books) differ depending upon one s course load. C reflecs he coss associaed wih full-ime enrollmen, while C reflecs he coss associaed wih par-ime enrollmen. Similarly, G is he lengh of ime i akes o graduae when enrolled fullime, and G is he lengh of ime i akes o graduae when enrolled par-ime. The subscrip reflecs he passage of ime and paricularly he accumulaion of employmen experience. Thus he earnings of boh high school graduaes (W HS ) and college graduaes (W C ) are allowed o vary 7

9 wih ime since graduaion (likely a a decreasing rae). The subscrip o he college earnings measure is more complex ( G 1) han ha for high school earnings () because he subscrip is adjused o equal zero in he period immediaely following graduaion from college. The wage funcion and γ are discussed in furher deail below. Equaion (1) reflecs he ne presen value (NV) associaed wih aending college on a full-ime basis; equaion (2) he NV associaed wih aending college on a par-ime basis. Enrollmen inensiy will be deermined by which value is greaer. our facors are permied o have an effec on NV ha differs by enrollmen inensiy: (1) ime ill graduaion (G), (2) direc enrollmen coss (C), (3) he fracion of earnings an enrolled individual can expec o receive relaive o he earnings of one who is no enrolled bu acively engaged in he labor force (γ), and (4) pos-graduaion wages (W C ). We assume ha i akes longer o graduae when enrolled par-ime han when enrolled full ime (G > G ). Given ha a cerain number of credis mus be earned o graduae and par-ime sudens receive fewer credis per erm, his assumpion is quie reasonable. We also assume ha he per erm enrollmen cos is greaer for full-ime han for par-ime sudens (C > C ). While i is ypically less expensive per credi o enroll full-ime, par-ime enrollmen does cos less per erm. The relaion beween enrollmen inensiy and G and C is reasonably self-explanaory; he relaion beween enrollmen inensiy and γ and W C is more complex. The earnings muliplier, γ, may differ by enrollmen inensiy for hree reasons. irs, as observed above, sudens enrolled par-ime work significanly more hours per week han sudens enrolled full-ime, wih seveny percen employed full-ime as compared wih only sixeen percen of hose enrolled full-ime. Second, i is well known ha, all else consan, average hourly earnings are generally higher on full-ime jobs han on par-ime jobs. Third, 8

10 par-ime jobs are disproporionaely likely o be in he low wage service secor of he economy (ie. all else is no consan). Thus, γ would be no less han γ because on average par-ime sudens are employed more hours per week han full-ime sudens and because full-ime workers are likely o be paid more per hour on average. urher analysis (repored in Appendix A) suggess ha 0 γ < γ 1 wih a mos one of he equaliies binding. The fourh enrollmen-dependen erm is pos-graduaion earnings. The pos-graduaion earnings sream (W C ) is expeced o differ depending upon he work experience garnered boh during and afer college. I is modeled as a funcion of γ, G, and ime pos-graduaion (he subscrip described above). As discussed in he previous paragraph, on average hose enrolled full-ime work fewer hours per week han hose enrolled par-ime. Thus, hose enrolled fullime accumulae less work experience for each year enrolled. The ype of work experience acquired by hose enrolled full-ime is also likely o be differen han ha acquired by hose enrolled par-ime. ull-ime workers who are par-ime sudens are more likely o be employed in career-relaed jobs han full-ime sudens who usually are consrained o find employmen ha will fi around heir class schedule. Career-relaed job experience will be valued more highly pos-graduaion han simple service secor jobs. Thus, he higher is γ, he higher is W C. The duraion of he enrollmen period (G) maers in ha he longer is G, he more job experience one is likely o obain while enrolled. inally, pos-graduaion earnings will be a funcion of pos-graduaion experience. The higher is -G, he higher is W C, wih wage growh ypically rising wih experience bu a a diminishing rae. The complexiy of his siuaion is bes illusraed wih an example. Consider wages in period = 9. An individual who wen o college full-ime and finished in four years may have accumulaed four years of some par-ime job experience and five years of pos-graduaion 9

11 experience in a career pah posiion. An individual who wen o college par-ime while working full-ime and finished in eigh years will have accumulaed eigh years of more inense pregraduaion work experience bu only one year of pos-graduaion experience. Off-hand i is no possible o say whose earnings would be higher a = 9. urher discussion of his issue is presened below. The assumpions so far include: C > C (3) G > G 0 γ < γ 1 wih no more han one of he final equaliies binding 6. Given hese assumpions, he difference beween he NV associaed wih par-ime enrollmen and ha associaed wih full-ime enrollmen can be expressed as follows: (4) NV G = G T = G College C W C G NV + γ 1 W College HS = W ( 1+ r) ( γ, G ) C ( γ, G ) W ( γ, G ) ( 1+ r) G = 0 C G G C 1 1 C + ( γ γ ) ( 1+ r) + W HS + When his expression is posiive, he NV of aending par-ime exceeds he NV of aending full-ime and he individual would enroll par-ime. The firs erm of equaion (4) will be posiive given he assumpions regarding C and γ. The second erm is likely negaive as he 6 As argued in he appendix, i is likely ha 1 > γ since oherwise few would choose o sop heir educaion. 10

12 wages of newly mined college graduaes are ypically higher han hose of high school graduaes of he same age 7. This implies ha HS W is less han W C G 1 even wihou he addiion of par-ime enrollmen coss (γ or C ). Similarly i seems reasonable o assume ha he final erm will be negaive in mos cases, since earnings end o rise quie rapidly wih experience for college graduaes and pre-graduaion experience is likely o coun less han pos-graduaion experience. If his is he case, hen par-ime enrollmen will be more aracive o hose closer o reiremen (wih a lower T), as his will lower he disadvanage of par-ime enrollmen, provided i is sill worh enrolling a all 8. More generally, when comparing par-ime and full-ime enrollmen his model suggess ha par-ime enrollmen will be more likely he lower he direc coss of par-ime enrollmen (C ) relaive o he direc coss of full-ime enrollmen (C ), he higher he earnings of hose enrolled par-ime as compared o hose enrolled full-ime (suggesing a higher W HS, a higher γ, and a lower γ ), he greaer he ime spen enrolled full-ime (G ) relaive o he ime spen enrolled par-ime (G ), he lower he wages for a college graduae who enrolled full-ime relaive o he wages for a college graduae who enrolled par-ime, he higher he discoun rae (r), and, generally speaking, he lower is T. Good employmen opporuniies for high school graduaes will make college enrollmen less aracive in general, and full-ime enrollmen less 7 The 1990 Census indicaes ha he earnings of full-ime, full-year male high school graduaes beween he ages of 25 and 29 average abou $22,360 while hose of full-ime, full-year male college graduaes beween he ages of 18 and 24 are $23,430 (hp://govinfo.kerr.ors.edu). 8 One is beer off enrolling par-ime han no enrolling when G C (1 γ ( 1+ r) ) W HS + T W C G 1 ( γ, G ) ( 1+ r) W HS = 0 = G + 1 more likely he lower is C, W HS, and r; he higher is W C, γ, and T. The impac of G is indeerminae as higher values exend he coss and increase he benefis. > 0 This is 11

13 aracive han par-ime enrollmen. Good employmen opporuniies may arise in he form of low unemploymen raes and/or high high-school relaive o college graduae wages. ar-ime enrollmen may be paricularly aracive o older individuals who chose o work afer compleing high school, as hese individuals will have a greaer opporuniy cos, due o heir employmen experience, and a lower T. In general, his model suggess ha employmen opporuniies are a key facor in he enrollmen decision. However, par-ime enrollmen may be chosen for reasons unrelaed o employmen as well. or example, individuals opporuniy cos of ime may be driven no only by employmen, bu also by household responsibiliies. Those bearing greaer household responsibiliies could choose o delay enrollmen and/or o enroll on a par-ime basis. Such family responsibiliies may also impar a gender bias as men and women may experience differen pressures. Married men and men wih children may feel more pressure o be breadwinners now (may have a higher curren opporuniy cos) and may be less inclined o enroll and, if enrolled, less likely o enroll full-ime. Women wih young children may be less likely o enroll and, if enrolled, less likely o enroll full-ime, a leas unil he children are of school age. By comparison wih hose who delay college in order o acquire work experience, however, women who delay college on accoun of household responsibiliies may be more likely o enroll as full-ime sudens, because heir poenial earnings while enrolled are smaller. Alernaively, he opporuniy cos of college may be a funcion of academic abiliy and/or financial circumsances. Less able sudens may need more ime o sudy han more able sudens in order o mainain an accepable GA, especially if hey are working. Less able sudens may no be able o ranslae an hour of sudy ime ino a desired grade oucome. If hese sudens are less producive per hour of sudy ime, hen achieving a arge grade requires more 12

14 sudy effor and ime. This could be modeled by making he opporuniy cos of college a funcion of abiliy level as well as enrollmen saus, wih more able individuals having lower coss paricularly when enrolled full-ime. Imperfec capial markes and financial consrains may also increase he cos of full-ime enrollmen relaive o par-ime enrollmen for some lower income sudens and dissuade hem from enrolling full-ime. The lower one s income, he greaer he value assigned o he nex dollar of earned income. Each of hese facors needs o be considered in he empirical esimaion o follow. Daa The daa se we use is he 1990/94 Beginning os-secondary [BS] resriced-access survey available from he NCES. These daa consis of a naional sample of individuals who aended a pos-secondary insiuion for he firs ime in he academic year. We resric our analysis o include only hose individuals who were seeking a degree (associaes or higher) and enrolled in an academic raher han a echnical degree program during his year. Those seeking cerificaes are excluded and enrollmen in echnical programs by hose seeking an academic degree is ignored. This reduces he sample size from 7253 o 5481 individuals 9. or his sample, he BS provides a wealh of personal and household daa. Informaion on gender, race, ehniciy, and age is available for virually every responden. Unlike he NLS or he HS&B surveys, he BS does no resric he sample by age. The younges respondens are eenagers; he oldes are in heir 60 s. Informaion on marial saus and household composiion 9 Also excluded a his sage were individuals who were only enrolled in he summer of (13), who graduaed in less han wo years (6), and who were seleced ino he sample because hey were aending a less-han-wo-year insiuion (13). I was necessary o remove he laer individuals in order o accuraely conrol for he complex sample design because all enrollmen a less han wo-year insiuions was excluded from analysis. urher deails regarding he 13

15 is recorded as is self-repored academic abiliy, parenal educaion, and employmen saus. Mached o his daa se is informaion on economic opporuniy garnered from he Census Bureau and he Deparmen of Labor Saisics. Resricing he sample o hose for whom no key variables are missing brings he sample o Sample saisics by iniial enrollmen saus are repored in Table 1 for hese individuals. All saisics and significance levels ake ino accoun sampling weighs, clusering, and sraificaion, as is necessary o fully accommodae he complex sample design of he BS (see Dowd 2001 for furher informaion). The fracion iniially enrolled par-ime as calculaed wihou he weighs is 7.5%. The weighed incidence is, however, 18.1%, indicaing ha hose iniially enrolled par-ime were under-sampled relaive o hose iniially enrolled full-ime. This weighed incidence is comparable o he naional esimae of 21.6% for degree seeking, firs-ime freshmen who were enrolled par-ime during he fall of An analysis of he individual specific characerisics by enrollmen saus, repored in Table 1, reveals a number of noable resuls. or example, race (p-value 0.79) and gender (pvalue 0.82) do no differ significanly by iniial enrollmen saus. However, Hispanic ehniciy does (p-value 0.00). Of hose iniially enrolled full-ime, only 5.6% are Hispanic as compared wih 15.6% of hose iniially enrolled par-ime 11. Thus, while 18% of he sample was enrolled par-ime, 38% of Hispanics chose par-ime enrollmen. sample selecion crieria are available in Appendix B. 10 The majoriy of he exclusions a his sage (798) were caused by failure o repor wheher iniial enrollmen saus was full-ime or par-ime he dependen variable in his analysis. Anoher fify-five individuals failed o self-describe heir mah abiliy. Only nineeen oher observaions were excluded due o missing values. 11 Jamieson, Curry, and Marinez (2001) also noe he frequency wih which Hispanics choose par-ime over full-ime enrollmen. 14

16 Anoher individual-specific characerisic ypically included in enrollmen sudies is academic abiliy. As discussed earlier, less able sudens are hypohesized o find full-ime enrollmen more cosly in erms of hours devoed o sudy ime o mainain grades han more able sudens. Unforunaely, he abiliy measure ypically used, SAT/ACT score, is missing for almos half his sample. A disproporionae share of hose missing daa are enrolled par-ime. A measure ha is almos universally available is a self-raed skill measure. Individuals were asked o self-rae heir academic skills as eiher above average, average, or below average. These skill measures were significanly posiively correlaed wih boh SAT and ACT es scores for ha populaion for which boh were repored. Informaion on self-repored mah skills is used in his sudy as mah skills were found o be a more significan deerminan of iniial enrollmen saus han eiher self-repored overall or verbal skills. A es of he hypohesis ha self-repored mah abiliy is uncorrelaed wih iniial enrollmen saus is rejeced a even he 1% significance level. 32% of respondens enrolled full-ime repor having above average mah skills as opposed o 17% of respondens enrolled par-ime. Anoher measure of academic abiliy is he ype of high school degree he responden received. A dummy variable is creaed ha akes on a value of one when he responden received a GED or oher cerificae in lieu of a high school diploma. As expeced, hose wihou a radiional high school diploma are more likely o enroll iniially on a par-ime basis. Thus boh abiliy measures sugges ha less able sudens are more inclined o ry ou college by enrolling par-ime raher han full-ime. amily background measures are included o capure boh psychological and financial suppor for educaional goals. Individuals whose parens have aended college are presumed o be more likely o have heir parens suppor for higher educaion. Simple saisics provide 15

17 some evidence for his hypohesis. While 57% of hose enrolled full-ime repor ha a leas one of heir parens compleed college, only 28% of hose enrolled par-ime repor he same background. Overall, he hypohesis ha parenal educaion is similar for hose enrolled fullime and hose enrolled par-ime is rejeced (p-value 0.00) 12. As expeced individuals who are enrolled par-ime are more likely o be older, independen from heir parens, married, and/or have children of heir own. Women are more likely han men o have children and o have been married a some poin, suggesing a possible gender bias in erms of household responsibiliies. While he BS conains subsanial informaion on he insiuion aended, we chose no o include such variables in he analysis. Two-year insiuions are far more likely o offer/encourage par-ime enrollmen han are four-year insiuions. Individuals who choose o aend wo-year insiuions may do so because of his flexibiliy. Thus, he choice of insiuion (and hence insiuional characerisics) will likely be a funcion of he enrollmen inensiy decision raher han a deerminan of i. The final rows presen informaion peraining o he earnings poenial of he respondens. The unemploymen rae in he respondens sae of residence is incorporaed o capure he probabiliy of finding a job. These daa were obained from he 1989 CS. The sample saisics indicae ha on average unemploymen raes are higher for hose enrolled full-ime han for hose enrolled par-ime. No only he probabiliy of finding a job bu he earnings one would expec o receive on such a job are imporan. Theory indicaes ha he higher an individual s earnings wihou a college degree, he more likely such an individual will be o enroll par-ime because his/her 12 Due o well-documened concerns (Adelman 1999) regarding sudens knowledge of heir parens educaion, we used parenal self-repors whenever possible. In less han hiry percen of he cases, hese repors were no available and an alernaive measure was used. In less han 16

18 opporuniy cos of ime will be greaer. Informaion on he average earnings of full-ime, fullyear workers wih a high school degree is available by gender, age, race, and ehniciy 13. Sample saisics indicae ha hose enrolled par-ime do have higher poenial earnings han hose enrolled full-ime ($17,000 versus $15,000). os-graduaion earnings also play a role in he heoreical model. A any age (), such as age 35, he enrollmen inensiy decision has wo effecs on income. Individuals age 35 who aended college full-ime and graduaed a he radiional age of 22 will have 13 years of posgraduaion experience bu relaively lile pre-graduaion experience. Individuals who aended college par-ime graduae a an older age. They may have more overall work experience by age 35 bu will have less pos-graduaion work experience. os-graduaion experience is a more significan deerminan of wages han pre-graduaion experience, so ha holding age consan he earnings of hose who aended college full-ime are likely higher han he earnings of hose who aended college par-ime. Unforunaely no measure of he magniude of his difference is available. Census daa repor only he average earnings of all college graduaes of a paricular age. This measure does no disinguish beween hose who aended college on a full-ime versus par-ime basis or beween hose who aended college a he age of 18 versus he age of 30. We consruced several alernaive measures of he reurn o a college educaion, bu none were saisically significan and none capures he essence of he hird erm in equaion (4). To capure somehing of he foregone earnings in he second erm of equaion (4), we include a measure of he raio of college o high school earnings for full-ime, full-year workers wih wo percen of he cases a missing values indicaor is used. 13 We disinguish only beween whie non-hispanic, black non-hispanic, whie Hispanic, black Hispanic, and Oher in maching daa by race and ehniciy due o boh concerns abou sample size and concerns abou informaion available o he respondens. These daa are obained from he 1990 Census and reflec earnings in

19 approximaely no experience, differeniaed by gender and race/ehniciy bu no age. This measure exhibis relaively lile variaion wihin he daa, ranging from a low of 1.58 o a high of 1.94 wih a mean of 1.91, and as such may no have a well-esimaed effec. Given our inabiliy o adequaely conrol for pos-graduaion earnings, he esimaed coefficien o he high school earnings measure may be biased, if pos-graduaion earnings are posiively correlaed wih curren earnings poenial and are an imporan deerminan of enrollmen inensiy. All he economic opporuniy cos variables discussed hus far are of a general naure and would be appropriae in a reduced form specificaion of enrollmen saus. These measures do no ake ino accoun he acual employmen saus of he responden, only his/her poenial employmen saus. Given ha enrollmen and employmen are likely o be joinly deermined, his is he preferred approach. However, he influence of economic facors on enrollmen inensiy may be a funcion of labor force aachmen. Wihin he BS here exiss addiional informaion ha may be used o proxy for labor force aachmen. Specifically, individuals are asked wheher heir choice of college was dicaed in par by heir abiliy o work while enrolled. We use his quesion o consruc a dummy variable (Work is Very Imporan) ha akes a value of one for hose individuals who reply ha i was very imporan ha hey choose a school ha enabled hem o work while enrolled. Of hose iniially enrolled par-ime, 72% agree wih his saemen; of hose iniially enrolled full-ime only 35% agree wih his saemen. This measure does no reflec acual oucomes, only inenions, and so may be exogenous wih respec o enrollmen saus and ye proxy for labor force aachmen. To be conservaive, we esimae wo basic specificaions (1) a purely reduced form model and (2) a specificaion including his measure of labor force aachmen. 18

20 The Iniial Enrollmen Inensiy Decision Using he BS daa, we esimae a probi model of he iniial enrollmen inensiy decision, condiional upon he decision o enroll. The dependen variable in his analysis akes a value of one for hose individuals who enroll on a par-ime basis during heir firs college erm. Resuls are repored in Table 2 for hree differen specificaions. The firs are as described above: he reduced form specificaion (1) and he parameerizaion ha conrols for labor force aachmen (2). The las (2 ) includes ineracion erms ha allow he role of he economic facors o differ depending upon labor force aachmen. All parameer esimaes are adjused for he complex survey design of he BS, aking ino accoun he weighs, clusering, and sraificaion of he sample 14. osiive coefficien esimaes indicae ha respondens wih higher characerisic values are more likely o aend par-ime. The resuls from specificaion (1) are for he mos par similar o hose repored in he univariae saisics. Hispanics are significanly more likely o enroll par-ime (p-value = 0.000), while race does no appear o be a significan facor (p-value = 0.66). inancial independence is also saisically insignifican (p-value = 0.45) as (in resuls no repored here) is household income. This finding suggess ha financial consrains are eiher no imporan or do no differ by enrollmen inensiy, conrary o our expecaions, bu similar o resuls repored by Clofeler (1991, p. 75). In conras o he univariae resuls, his mulivariae analysis indicaes ha, holding all else equal, women are less likely o enroll par-ime han men (p-value = 0.049). The mos significan finding amongs he individual specific characerisics is ha older persons are more likely o enroll par-ime (p-value = 0.00) 15. This resul suppors he predicions of he 14 In paricular, we employ he SYV commands wihin STATA. Again, see Dowd (2001) for furher informaion. 15 In resuls no repored here we used a series of dummy variables o measure age raher han 19

21 heoreical model ha condiional upon enrollmen, for older persons he shorer pos-graduaion earnings benefi associaed wih full-ime enrollmen makes he lower opporuniy cos associaed wih par-ime enrollmen more aracive. Surprisingly, we found (in resuls no repored here) ha older women were jus as likely o enroll on a par-ime basis as older men. However, while here are no gender specific age effecs, marial and parenal saus effecs do differ by gender, as migh be suggesed by gender differences in household responsibiliies. Abiliy measures influence he enrollmen inensiy decision as expeced. Those reporing above average mah skills are less likely o enroll par-ime, perhaps indicaing ha hey find full-ime enrollmen less cosly han average or less able sudens. The same relaion also holds when measures of self-repored verbal or overall academic abiliy are used bu i is mah abiliy ha is mos highly correlaed wih enrollmen inensiy (p-value = for mah abiliy versus for verbal and for academic abiliy). The impac of parenal educaion is significan (p-value = 0.001), bu non-linear. As compared wih hose whose mos educaed paren compleed college, hose whose mos educaed paren compleed only high school or sared bu did no complee college were significanly more likely o enroll par-ime. Such individuals may receive less suppor when pursuing a college degree. However, hose whose parens failed o complee high school are no significanly more likely o enroll par-ime han hose whose parens compleed college. One would expec hese individuals o receive even less suppor, bu his lack of suppor may manifes iself more in he decision o enroll raher han in he enrollmen inensiy decision. he mix of coninuous (age and age squared) and dummy (eenagers) variables employed here. We found significan differences in enrollmen inensiy decisions beween hose age 18 and 19, 19 and 20, 24 and 25, and 34 and 35. The resuls obained from his specificaion are similar o hose repored here, hough he fi of his alernaive specificaion was slighly worse using boh -es and prediced oucome measures of goodness-of-fi. 20

22 The role of household characerisics is expeced o differ by gender as a resul of gender differences in household responsibiliies. This hypohesis receives some suppor as he impac boh of marial saus (p-value = 0.09) and of children (0.08) is saisically significan for men, wih boh marriage and children increasing he probabiliy of par-ime enrollmen for men. However, his was no he case for women (p-value = 0.42 and 0.31 for marriage and children respecively). Only he presence of school age children has a marginally significan impac for women, increasing he probabiliy of aending full-ime, presumably because more ime is freed in he home once children sar going o school. More generally, i may be he case ha marriage and children primarily affec he enrollmen decision for women, raher han he enrollmen inensiy decision. In a more general es for gender differences, we inerac gender wih every oher variable in he analysis. Joinly hese addiional variables have a p-value of 0.65 and only one variable is individually significan a even he 10% level. These resuls indicae ha i is no unreasonable o pool men and women in a single sample. The oher measures of opporuniy cos are economic in naure. The impac of he unemploymen rae on enrollmen inensiy is negaive as expeced wih a p-value of The higher he unemploymen rae in an individual s sae of residence, he higher is he probabiliy wih which ha individual will enroll full-ime. The marginal p-value associaed wih his measure could be aribued o is lack of variaion. If i were only he absolue level of he unemploymen rae a he ime of enrollmen ha maered, hen addiional variaion could be inroduced by consrucing a measure of he unemploymen rae ha reflecs he age, race, ehniciy, and even educaion level of he responden. However, i is likely he relaive level of unemploymen a he ime of enrollmen ha maers. A black eenager, who faces an unemploymen rae of 20%, may be less likely han a whie eenager, facing an unemploymen 21

23 rae of 15%, o enroll par-ime because a 20% unemploymen rae is relaively low for a black eenager while a 15% unemploymen rae is relaively high for a whie eenager 16. We did esimae he model (resuls no shown) using saewide unemploymen raes ha differed for eenagers. These resuls suppor our finding ha higher unemploymen raes are associaed wih lower par-ime enrollmen probabiliies, bu he magniude of he effec is smaller, presumably o moderae he greaer variaion in he unemploymen rae observed for eenagers. The variaion in he cross-sae unemploymen rae ha idenifies he coefficien o he unemploymen rae in he resuls repored probably more closely mimics he local and possibly emporary economic condiions ha are more likely o influence enrollmen inensiy decisions. The final wo variables included in specificaion (1) are he expeced earnings measures. The firs measure represens expeced earnings of he responden if he/she worked full-ime and did no aend college. The second measure is an esimaed raio of his/her college o high school graduae earnings. Theory predics ha he firs erm should have a posiive coefficien, as higher curren earnings are possible when one is enrolled par-ime (γ > γ ). If he raio measure is accurae no maer one s experience level, he laer erm should have a negaive coefficien. The acual esimaes have he opposie signs. The raio measure is never saisically significan, perhaps indicaing i is a poor measure of relaive earnings. The high school graduae earnings measure is saisically significan (p-value = 0.064) and may be posiive because i is indicaive of no only relaive high-school earnings bu also expeced college earnings. Those expecing high earnings pos-graduaion would wan o aain hose higher earnings faser by aending college full-ime. Several alernaive specificaions were aemped wih ineracions beween 16 The relaive unemploymen rae following graduaion and he unemploymen differenial beween hose who aend college par-ime versus full-ime will also influence he enrollmen inensiy decision, bu such deailed measures are no available. 22

24 age and earnings, age and raio, he absolue wage difference beween college and high school graduaes wih lile experience, and he percenage wage difference beween college and high school graduaes wih lile experience - o no avail. Basically, here is no clear proxy for he relaive earnings of college graduaes who enrolled full-ime versus hose who enrolled parime. In order o es he robusness of he model, paricularly he economic facors, we reesimaed he model resricing he sample o include only hose under age 19. These resuls (available upon reques) were quie similar o hose from he unresriced sample wih ehniciy, abiliy, and marial saus having approximaely he same effec on enrollmen inensiy. Wihin his sample, blacks were found o be more likely o enroll par-ime, bu no women. oenial earnings has a posiive effec, meaning ha hose whose expeced earnings wih a high school degree are higher are more likely o enroll par-ime. This is as we originally prediced. However, hose wih higher pos-graduaion earnings were also more likely o enroll par-ime, conrary o our expecaions bu readily aribuable o poor measuremen. Mos imporanly, he unemploymen rae coninues o have a negaive impac on inensiy. This relaion is somewha sronger when he average unemploymen rae for eenagers wihin he sae is used, bu is significan (p-value 0.07) even when using he unemploymen rae for persons of all ages. Boh resuls demonsrae he robusness of he unemploymen rae effec o he choice of sample. Specificaion (2) adds a conrol for he responden s labor force aachmen by conrolling for he imporance assigned o employmen. The resuling specificaion provides a beer fi of he model as measured by boh he fracion of observaions correcly prediced and he mean sum of he squared residuals. However, inclusion of his measure of labor force aachmen has relaively lile impac on he coefficiens o he non-economic relaed variables in he model. 23

25 The economic measures, no surprisingly, are less precisely esimaed. In specificaion (2 ) we inerac he Work is Very Imporan variable and he economic facors o es he hypohesis ha he effec of economic facors differs wih he responden s labor force aachmen. The join p-value on he ineracion erms is 0.11 and he direcion of he effecs makes logical sense. or example, he impac of he sae s unemploymen rae is greaer for hose for whom work is no very imporan, perhaps because hose for whom i is imporan already have a job and hence are no as worried abou heir probabiliy of finding a job. In addiion, he impac of he high school earnings variable is negaive and saisically significan only for hose for whom work is no very imporan or labor force aachmen is low. Those more aached o he labor force may consider earnings poenial more of a curren opporuniy cos han a pos-graduaion gain. In order o beer undersand he magniude of he coefficien esimaes repored in Table 2, we calculae he prediced probabiliy individuals wih various characerisics will enroll parime. Table 3 presens hese prediced probabiliies. The base case agains which all comparisons are made is ha of: an 18-year-old whie, non-hispanic male wih a high school diploma, average mah abiliy, living in a sae wih he sample average unemploymen rae (5.2%), and having parens upon whom he is sill dependen and who hemselves compleed college. The opporuniy cos and raio measures are hose for whie, male, non-hispanic eenagers. Columns (1) and (2) presen resuls from he reduced form specificaion (1). One complicaion inroduced o hese predicions is ha a change in he gender, race, ehniciy, and/or age of an individual generally changes he value of several variables in he model. or example, o predic he iniial enrollmen saus of a woman, one would need o change he value of he variable emale o 1 as well as change he value of he wo earnings 24

26 measures o reflec he differen average earnings poenial of women as compared o men. To predic he iniial enrollmen saus of an older person, he value of Age and Age Squared would of necessiy change, bu so would he measure of poenial high school graduae earnings, as his measure is also age dependen. In order o illusrae how a change in only he indicaor variables and no he earnings measures would affec he iniial enrollmen oucome, we presen wo ses of predicions for he reduced form specificaion (1). redicions ha mainain he base case earnings values (hose for a whie, non-hispanic male age 18) are presened in column (1). redicions ha change all gender, race, ehniciy, and age relaed values are presened in column (2). Column (1) is lef blank where he adjused and unadjused measures are idenical. The prediced probabiliy of par-ime enrollmen for an individual wih base case characerisics using he reduced form model (specificaion 1) is 5.7%, considerably lower han he sample average probabiliy of 18.1%. The coefficien for emale is significan and negaive in he model. This indicaes ha women have a significanly lower probabiliy of enrolling parime han men, holding all else equal. Indeed, holding all else equal, a woman wih base case characerisics has only a 2.7% probabiliy of iniially enrolling par-ime. However, women have subsanially lower expeced earnings han men ($13,272 versus $16,745 for he base case) and when hese are aken ino accoun (see column 2), heir probabiliy of par-ime enrollmen is no subsanially or significanly differen from ha for men (5.9% for women versus 5.7% for men). Being black and being Hispanic increase he probabiliy of par-ime enrollmen, all else equal (o 8.0% and 25.0% respecively). Accouning for he lower expeced earnings of hese groups furher widens he differenial beween full-ime and par-ime enrollmen raes. Approximaely fifeen percen of he difference beween he fully adjused Hispanic enrollmen probabiliy and he base case enrollmen probabiliy is due o earnings differences. 25

27 The impac of he unemploymen rae is gauged by comparing he par-ime enrollmen probabiliy for an individual living in a sae wih a 5.2% unemploymen rae wih ha of an oherwise similar individual living in a sae wih a 3.2% unemploymen rae. This 2.0 percenage poin change in he unemploymen rae leads o a 2.6 percenage poin or 45% increase in he probabiliy of enrolling par-ime. These predicions demonsrae ha he unemploymen rae as a measure of opporuniy cos no only has a significan effec on par-ime enrollmen probabiliies, bu also a subsanial one. The remainder of Table 3 demonsraes he remendous imporance of age and marial saus for men and women. While proclaiming independen saus has lile influence on he probabiliy of par-ime enrollmen, age does have a significan effec. Being independen and age 25 increases he probabiliy of par-ime enrollmen by a facor of almos en, all else equal (o 55.7%). However, older persons have higher earnings, which acs o decrease heir probabiliy of par-ime enrollmen, in his case o 33.7%. redicions for specificaion (2) are presened in column 3 of Table 3. The base case for specificaion (2) addiionally assumes ha work is no very imporan. All hese predicions are fully adjused for earnings differences by gender, race, ehniciy, and age. Of ineres is he finding ha he prediced probabiliy of par-ime enrollmen is much smaller under he base case and he impac of he labor force aachmen measure subsanial. The probabiliy ha an individual wih base case characerisics is enrolled on a par-ime basis falls from 5.7% in he reduced form model o 3.1% in he model specifying ha work is no imporan. The probabiliy of being enrolled par-ime hen increases by a facor of four o 12.5% if an individual wih oherwise base case characerisics saes ha work is very imporan. Conrolling for labor force aachmen clearly has a significan impac upon prediced enrollmen 26

28 saus, hough we remain concerned abou possible simulaneiy bias in hese esimaes. Conclusion Mos research sudies dealing wih college enrollmen have, for a variey of reasons, focused on full-ime sudens and eiher ignored par-ime enrollmen or reaed full-ime and par-ime enrollmen as he same aciviy. Ye par-ime sudens are observed making subsanially differen choices boh in he labor marke and in he educaion area han full-ime sudens. We exploi hese differences o examine he facors associaed wih enrollmen inensiy: he decision o iniially aend college on a par-ime raher han full-ime basis. A concepual model derived from human capial heory is developed o idenify facors ha affec he decision o aend par-ime versus full-ime. This model predics ha older individuals and hose wih higher curren opporuniy coss will be more likely o aend par-ime. Using a naional sample of undergraduaes from he BS 90/94 daa se and condiioning on he decision o enroll, we find subsanial evidence supporing his heoreical model. A probi specificaion of he empirical model suggess ha no only do personal and household characerisics affec he decision o aend par-ime (for example, Hispanics and married men are significanly more likely o aend par-ime), bu also ha age and economic facors play an imporan role. Older persons are significanly and subsanially more likely o enroll par-ime. In addiion, for he modal suden each one percenage poin decrease in he unemploymen rae can increase he probabiliy of par-ime enrollmen by more han one percenage poin. There is some evidence ha he impac of he unemploymen rae is greaer for hose no currenly in he labor marke. Lower expeced earnings also lead o higher par-ime enrollmen probabiliies. There is some evidence ha his effec is greaer for hose now less aached o he labor force, 27

29 who may be less likely o rea expeced earnings as an opporuniy cos. Several quesions remain. While he presence of school age children increases he probabiliy ha women will aend college full-ime, hese resuls hold only condiional upon he decision o aend college a all. I would be of ineres o joinly esimae he decision o aend and he inensiy decision, preferably using an uncondiional specificaion and exending he analysis o consider persisence as well as enrollmen. Our model poins ou he imporan impac pre-graduaion work experience can have on pos-graduaion earnings, bu we were unable o obain daa disinguishing beween earnings by eiher enrollmen inensiy or pregraduaion work experience. More deailed daa would permi a more complee es of his heory. The role of cos facors was also idenified heoreically, bu no empirically. We only had daa on full-ime uiion raes, no par-ime raes, and on financial aid opporuniies condiional upon enrollmen inensiy. urher research disinguishing beween he ne cos of college for par-ime and full-ime enrollmen would aid idenificaion of he model. Exending he model o disinguish beween wo and four-year insiuions, beween residenial and commuer-oriened insiuions, could aid insiuional researchers in heir analysis. olicy makers seeking o expedie graduaion need o beer undersand he enrollmen decisions sudens make when hey ener college. The decision o aend college par-ime clearly has a significan impac on one s expeced ime o graduaion as well as one s expeced income. This paper akes us a sep closer o undersanding he enrollmen inensiy decision. 28

30 Appendix A A urher Analysis of γ To see he imporance of γ, we considered wo exreme cases: a case in which γ = γ and a case in which γ >> γ. When γ = γ he opporuniy cos associaed wih college enrollmen is no a funcion of enrollmen saus and he wage of college graduaes is a funcion of enrollmen inensiy only indirecly via he ime spen enrolled. Then par-ime enrollmen would be preferred o full-ime enrollmen only if: ( A1) G = G T = G NV College C W C G NV + γw 1 HS College W ( 1+ r) = 0 ( G ) C ( G ) W ( G ) ( 1+ r) G = C G 1 G 1 C C ( 1+ r) + > 0 + This preference ordering is more likely: (1) he lower he cos of par-ime as compared o fullime enrollmen (C << C ), so ha he direc benefis aribuable o par-ime enrollmen are high; (2) he higher are he earnings of hose enrolled in college (γw HS ) relaive o college graduaes (W C ) and (3) he smaller he difference in ime o graduaion ( G G ), so ha he opporuniy coss associaed wih he exended enrollmen are smaller; (4) he more nearly job experience while enrolled is a subsiue for job experience following graduaion, so ha posgraduaion reurns are nearly equalized; and (5) he higher is he discoun rae (r), so he negaive value of he hird erm does no weigh so heavily. The firs and hird facors operae a odds wih 29

31 one anoher. Direc coss are ypically subsanially differen only when here is a subsanial reducion in credi hours, and hose aking subsanially reduced loads necessarily ake significanly longer o graduae. To evaluae facors wo, four, and five i is imporan o remember ha par-ime enrollmen will only be observed if par-ime enrollmen is preferred o no enrollmen a all. acors wo, four, and five sugges a smaller reurn o college graduaion as a whole and hence a lower probabiliy of aending no maer he inensiy. If γ = γ, par-ime enrollmen is unlikely o be observed a all, since i makes more sense o enroll eiher full-ime or no a all. When γ >> γ, he earnings poenial of hose enrolled par-ime is subsanially greaer han he earnings poenial of hose enrolled full-ime. In his case, par-ime enrollmen becomes more aracive relaive o full-ime enrollmen. In he limi γ = 1 and γ = 0, meaning ha par-ime college sudens can earn as much as high school graduaes, while full-ime college sudens do no work a all. In his siuaion, an individual would choose o enroll par-ime raher han forego college alogeher so long as he individual s higher fuure earnings as a college graduae recoup he direc coss of par-ime enrollmen. There would be no opporuniy cos associaed wih aending college if one aended par-ime and earned exacly wha a high school graduae could earn. Since he greaes cos associaed wih college is he opporuniy cos, in his exreme case virually everyone would prefer par-ime enrollmen o no enrollmen. Since we know many individuals choose no o go o college, his suggess ha in realiy γ mus be less han one. ar-ime enrollmen would be preferred o full-ime enrollmen when γ = 1 and γ = 0 so long as he higher near erm income benefis of par-ime enrollmen (C C + W HS > 0) were large enough o offse he lower fuure earnings (see he second and hird erms in equaion 30

32 (A2)). Lower fuure earnings arise boh because par-ime sudens graduae laer, hus begin receiving college graduae earnings laer, and because hose aending college par-ime have fewer years o enjoy higher pos-graduaion wages. ( A2) G = G T = G NV College C W C G + W 1 NV HS College W ( 1+ r) C G = 0 ( 0, G ) C ( 1, G ) W ( 0, G ) ( 1+ r) = G 1 G 1 C C ( 1+ r) + > 0 + W HS + However, i is also rue ha hose aending college par-ime accumulae some work experience while in college ha is likely o enhance heir pos-graduaion pay. No reurn for work experience is expeced on ime spen enrolled full-ime, if hose enrolled full-ime do no work. Bu holding pos-graduaion experience consan (a τ), he wages of hose who aended college par-ime will exceed he wages of hose who aended college full-ime if pre-graduaion C C experience is a all valuable in he pos-graduaion workplace : W (, G ) W ( 0, G ) 1 τ τ >. This earnings adjusmen will ac o reduce he fuure earnings differenial aribuable o parime raher han full-ime enrollmen, making par-ime enrollmen more aracive. Indeed, in his exreme case (γ = 1 and γ = 0), he benefis associaed wih par-ime enrollmen likely dominae he benefis associaed wih full-ime enrollmen. In his limiing case here is no opporuniy cos from foregone earnings associaed wih par-ime aendance and he only benefi o full-ime enrollmen is earlier graduaion o a college graduae s earnings. 31

33 These special cases shed ligh on he model by suggesing bounds on γ. When he opporuniy cos of aending college is no a funcion of enrollmen inensiy (γ = γ ), virually all hose aending would aend full-ime since he opporuniy cos of aending is no a funcion of enrollmen inensiy and par-ime aendance delays pos-graduaion earnings. When hose aending par-ime incur no opporuniy cos, par-ime enrollmen will likely be he dominan oucome since he direc coss of college are generally low relaive o he benefis. This is especially rue if hose enrolled full-ime are no employed a all (γ = 0) and so bear he full opporuniy cos of enrollmen. The fac ha a significan bu no dominan share of college sudens choose o aend par ime suggess ha γ > γ and boh mulipliers are no a boundary levels of 0/1. This is equivalen o saing ha here are differen opporuniy coss associaed wih differen enrollmen inensiies. 32

34 Appendix B urher Deails Regarding Sample Selecion Crieria The sample used in his analysis was creaed wih an eye o including only hose individuals seriously ineresed in pursuing an academic pos-secondary degree. To his end, we resriced he sample o include only hose individuals seeking more han a cerificae degree or (when his informaion was unavailable) o include only hose individuals who repor expecing o receive more han a rade school educaion boh in he 1990 survey and a leas one of he follow-up surveys. Thus, we exclude individuals who were no acively seeking an academic pos-secondary educaion. The NCES saff suggesed his resricion. Approximaely 75 percen of hose individuals excluded from our final sample were excluded on hese grounds. We also excluded enrollmen daa from insiuions offering less han a wo year program of insrucion and from non-academic wo and four-year insiuions. The decision o exclude aendance a all insiuions offering less han a wo-year program of insrucion was also quie sraighforward. irs, here were relaively few cases of such enrollmen wihin his sample. Of almos 45,000 erms for which aendance was repored over he 5 year inerval, only 745 represened aendance a less han wo-year insiuions. Second, NCES saff indicaed ha few credis obained a such insiuions could be used owards a bachelor s degree. In fac, over a hird of hese insiuions self-repored having no academic program! uhermore, less han en percen of he respondens repored receiving academic insrucion while enrolled a hese insiuions. The decision o exclude informaion from wo and four-year nonacademic insiuions was a more difficul one. In all, aendance informaion from 164 of 788 wo-year and 17 four-year insiuions was deleed. The schools ha were excluded a his sage were primarily bible schools, echnical or business colleges, miliary insiues, and beauy and ar 33

35 schools. Thus, even for hose individuals who repored seeking an academic degree, aendance a rade schools and culinary insiues was effecively no couned as enrollmen for he purposes of our sudy. A few individuals who were never enrolled in an academic insiuion despie expressing an ineres were eliminaed a his sage. We believe ha our sample includes all individuals who express an ineres in and acually enroll in an academic program (AA or higher). 34

36 References Adelman, C. (1999). Answers in he Tool Box: Academic Inensiy, Aendance aerns, and Bachelor s Degree Aainmen. Washingon, D.C.: U.S. Deparmen of Educaion. Bean, J.. & Mezner, B.S. (1985). A Concepual Model of Nonradiional Suden Ariion. Review of Educaional Research, 55 (4), Becker, G. (1975). Human Capial. New York: Naional Bureau of Economic Research. Becker, William. (1990). The Demand for Higher Educaion. In S.A. Hoenack & E.L. Collins, The Economics of American Universiies: Managemen, Operaions, and iscal Environmen. Albany: Sae Universiy of New York ress. Borus, M.E. & Carpener, S.A. (1984). acors Associaed wih College Aendance of High School Seniors. Economics of Educaion Review, 3 (3), Cabrera, A.., Sampen, J.O., & Hansen, W.L. (1990). Exploring he Effecs of Abiliy o ay on ersisence in College. The Review of Higher Educaion, 13 (3), Clofeler, C.T. (1991). Demand for Undergraduae Educaion. In C.T. Clofeler, R.G. Ehrenberg, M. Gez, & J.J. Siegfried, Economic Challenges in Higher Educaion. Chicago: The Universiy of Chicago ress. Corman, H. (1983). ossecondary Educaional Responses by Recen High School Graduaes and Older Aduls. Journal of Human Resources, 18 (2), Dickey, A.K., Asher, E.J. Jr., & Tweddale, R.B. (1989). rojecing Headcoun and Credi Hour Enrollmen by Age Group, Gender, and Degree Level. Research in Higher Educaion, 30 (1), Dowd, A.C. (2001). Compuing Variances from Daa wih Complex Sampling Designs: A Comparison of Saa and SSS. aper presened a he Norh American Saa Users Group. 35

37 Ehrenberg, R.G. & Sherman, D.R. (1984). Opimal inancial Aid olicies for a Selecive Universiy. Journal of Human Resources, 19 (2), Hoenack, S.A. & ierro, D.J. (1990). An Economeric Model of a ublic Universiy's Income and Enrollmen. Journal of Economic Behavior and Organizaion, 14 (3), Hoenack, S.A. & Weiler, W.C. (1975). Cos-Relaed Tuiion olicies and Universiy Enrollmens." Journal of Human Resources, 10 (3), (1979). The Demand for Higher Educaion and Insiuional Enrollmen orecasing. Economic Inquiry, 17 (1), Jamieson, A., Curry, A., & Marinez, G. (2001). School Enrollmen in he Unied Saes -- Social and Economic Characerisics of Sudens." Curren opulaion Repors, Ocober 1999, 7-9. Ligh, A. (1996). Hazard Model Esimaes of he Decision o Reenroll in School. Labour Economics, 2, Mcherson, M.S. & Schapiro, M.O. (1991). Does Suden Aid Affec College Enrollmen? New Evidence on a ersisen Conroversy. American Economic Review, 81 (1), Mezner, B.S. & Bean, J.. (1987). The Esimaion of a Concepual Model of Nonradiional Undergraduae Suden Ariion. Research in Higher Educaion, 27 (1), Moore, R.L., Sudenmund, A.H., & Slobko, T. (1991). The Effec of he inancial Aid ackage on he Choice of a Selecive College. Economics of Educaion Review, 10 (4), Sefor, N.S. & Turner, S.E. (2002). Back o School: ederal Suden Aid olicy and Adul College Enrollmen. Journal of Human Resources, 37 (2),

38 Seneca, J.J. & Taussig, M.K. (1987). The Effecs of Tuiion and inancial Aid on he Enrollmen Decision a a Sae Universiy. Research in Higher Educaion, 26 (4), Sarkey, J.B. (1994). The Influence of rices and rice Subsidies on he Wihin-Year ersisence by ar-ime Undergraduae Sudens: A Sequenial Analysis. h.d. diss., Universiy of New Orleans. Tynes, S.. (1993). The Relaionship of Social, Economic, Academic, and Insiuional Characerisics o ersisence of Nonradiional Age Sudens in Higher Educaion: Implicaions for Counselors. h.d. diss., Universiy of New Orleans. U.S. Bureau of he Census. (2002). On-line. Available hp:// U.S. Bureau of he Census. (1990). On-line. Available via he Governmen Informaion Sharing rojec a hp://govinfo.kerr.ors.edu under Earnings by Occupaion and Educaion. U.S. Deparmen of Educaion. (2001). Naional Cener for Educaion Saisics. Diges of Educaion Saisics, Available a hp://nces.ed.gov/pubs2002/diges2001. U.S. Deparmen of Educaion. (1998). Naional Cener for Educaion Saisics. Sopous or Sayous? Undergraduaes Who Leave College in Their irs Year. NCES by Laura Horn. rojec Officer: Dennis Carroll. Washingon D.C. Zucker, B. & Dawson, R. (2001). Credis and Aainmen: Reurns o os-secondary Educaion Ten Years Afer High School, Naional Cener for Educaional Saisics, (NCES Elecronic Caalog # ),

39 Table 1 Sample Characerisics by irs Term Enrollmen Saus Enrolled Characerisics ull-time ar-time emale 53.25% 54.14% Whie 85.73% 86.82% Black 8.39% 8.57% Oher Race 5.88% 4.61% Hispanic 5.57% 15.61% Self-Repored Mah Abiliy Above Average 32.18% 17.33% Average 51.11% 61.84% Below Average 16.71% 20.83% No High School Diploma 3.41% 7.97% Highes arenal Educaion Level a Less Than High School 5.29% 11.65% High School/Trade School 27.84% 43.62% Some College 8.36% 8.62% College or More 57.16% 27.80% Missing 1.35% 8.30% Teenager 89.33% 39.80% Age Age Squared No Dependen upon arens 10.17% 49.75% Marial Saus by Responden s Gender Men: Never Married 97.26% 74.79% Men: Married 2.33% 19.19% Men: Divorced, Separaed, Widowed 0.40% 6.02% Women: Never Married 92.84% 55.41% Women: Married 5.13% 34.62% Women: Div.,Sep.,Wid. 2.03% 9.96% 38

40 Number of Children b by Responden s Gender Men: # Less Than Age Men: # Age Men: # Age Women: # Less Than Age Women: # Age Women: # Age Unemploymen Rae in Home Sae 5.22% 5.13% Earnings of High School Graduae c $15.04 $16.89 Raio of College o High School Earnings d Work is Very Imporan 34.51% 71.91% Number of Observaions Unweighed ercenage of Observaions Weighed 81.92% 18.08% a As repored by he paren in over seveny percen of he cases. b Age is approximae. Those in he younges group were born afer 1981, hose lised as age 7-12 were born in , and hose lised as age were born in c Repored in housands of dollars per year and differeniaed by gender, age, race (Whie/Black/Oher), and ehniciy (for Whies and Blacks). Based on 1990 Census repors for full-ime/full-year workers. d Average earnings of year old college graduaes divided by average earnings of year old high school graduaes working T/Y and differeniaed by gender, race (Whie/Black/Oher), and ehniciy (for Whies and Blacks). Based on 1990 Census repors for full-ime/full-year workers. Excep as noed, all measures are calculaed using sample weighs. 39

41 Table 2 robi Model of Iniial Enrollmen Inensiy Specificaion Specificaion Specificaion Variables (1) (2) (2') Consan (5.3351) (5.1769) (5.8043) emale ** ** ** (0.1780) (0.1762) (0.1845) Black (0.3670) (0.3573) (0.3557) Oher Race (0.2308) (0.2367) (0.2265) Hispanic *** *** *** (0.2353) (0.2223) (0.2196) Above Average Mah Abiliy *** *** *** (0.1165) (0.1195) (0.1182) Below Average Mah Abiliy (0.1131) (0.1182) (0.1170) No High School Diploma ** ** ** (0.2392) (0.2232) (0.2269) Highes arenal Educaion Level Less han High School (0.2018) (0.1986) (0.1952) High School/Trade School *** *** *** (0.1100) (0.1149) (0.1151) Some College ** * * (0.1598) (0.1590) (0.1577) Missing (0.2500) (0.2550) (0.2633) Teenager *** *** *** (0.1802) (0.1827) (0.1850) Age ** ** ** (0.0791) (0.0794) (0.0853) Age Squared ** ** ** (0.0010) (0.0010) (0.0011) No Dependen upon arens (0.1821) (0.1826) (0.1804) Married Man * ** ** (0.3013) (0.2933) (0.2932) Sep/Div/Widowed Man * ** *** (0.4773) (0.5090) (0.6122) Married Woman * * (0.2399) (0.2353) (0.2341) Sep/Div/Widowed Woman

42 (0.2820) (0.2580) (0.2554) Number of Children Men: # < Age (0.2315) (0.2231) (0.4350) Men: # Age (0.2855) (0.2532) (0.2495) Men: # Age ** * (0.4187) (0.3967) (0.2320) Women: # < Age (0.1569) (0.1471) (0.1567) Women: # Age * * (0.1540) (0.1641) (0.1736) Women: # Age (0.1701) (0.1568) (0.1487) Unemploymen Rae in Home Sae * * * (0.0577) (0.0585) (0.0766) Earnings of High School Graduae * ** (0.0476) (0.0472) (0.0597) College/High School Earnings (2.7985) (2.7384) (3.0407) "Work is Very Imporan" *** (0.0904) (5.1748) "Work"*Unemploymen Rae (0.0845) "Work"*High School Earnings ** (0.0377) "Work"*College/High School Earnings (2.6441) -Tes Saisic racion Correcly rediced 85.9% 87.7% 88.0% Of Those Aending T 95.0% 95.7% 96.0% Of Those Aending T 44.4% 51.5% 51.4% Sum of he Squared Residuals Dependen variable has a value of 1 if responden iniially enrolled par-ime. All esimaes are adjused for sample weighs, clusering, and sraificaion. Asympoic sandard errors are repored in parenheses below coefficien values. * (**) [***] Indicaes saisical significance a he 10% (5%) [1%] level, 2-sided es. 41

43 Table 3 rediced robabiliy of Iniially Enrolling ar-time By Specificaion and Characerisics Specificaion Characerisic (1) (1) (2). Unadjused Adjused Adjused Base Case (0.013) (0.013) (0.010) emale (0.012) (0.012) (0.009) Black (0.053) (0.039) (0.026) Hispanic (0.074) (0.069) (0.060) Independen (0.030) (0.017) Independen & Age (0.088) (0.098) (0.078) Independen & Age (0.137) (0.159) (0.122) Independen, Age 35, emale (0.144) (0.119) (0.125) Independen, Married, Age 35 (0.163) (0.166) Independen, Married, Age 35, emale (0.104) (0.123) Unemploymen Rae = 3.2% Versus 5.2% (0.026) (0.020) Base Case + Work is Imporan (0.029) Asympoic sandard errors repored in parenheses beneah he prediced probabiliies. Unadjused means he earnings measures were unadjused for differences by gender, race, ehniciy, and age. 42

44 Base Case: Whie, non-hispanic male, having high school diploma, average abiliy, parens who compleed college, age 18, dependen, never married, and no children. Specificaion (2) addiionally assumes he responden did no indicae ha work was very imporan. 43