2. The econometric model

Transcription

1 Age Bised Technicl nd Orgnisionl Chnge, Trining nd Employmen Prospecs of Older Workers * Luc BEHAGHEL (Pris School of Economics (INRA) nd CREST) Eve CAROLI (Universiy Pris Duphine, LED-LEGOS, Pris School of Economics nd IZA) Muriel ROGER (Pris School of Economics (INRA) nd INSEE) Absrc We nlyse he role of rining in miiging he negive impc of echnicl nd orgnisionl chnges on he employmen prospecs of older workers. Using pnel of French firms in he le 1990s, we firs esime wge bill shre equions for differen ge groups. Consisen wih wh is found in he lierure, we find h doping new echnologies nd innovive work prcices negively ffecs he wge bill shre of older workers. In conrs, rining older workers more hn verge increses heir shre in he wge bill in he nex period. So, rining conribues o offse he negive impc of ICT nd innovive work prcices. However, i does no reduce he ge bis ssocied wih hese innovive devices: he inercion erms beween rining nd ICT/innovive work prcices re eiher insignificn or negive. As second sep, we esime he impc of ICT, innovive work prcices nd rining on employmen flows by ge group in he nex period. We ge similr resuls o hose obined wih wge bill shres. Overll, rining ppers o hve posiive impc on he employbiliy of older workers, bu i offers limied prospecs o dmpen he ge bis ssocied wih new echnologies nd innovive work prcices. Keywords: Technicl chnge; orgnizionl chnge; rining; older workers. JEL codes: J14; J24; J26; O30. * We re greful o Hélène Grner, Dominique Goux, Céline Théveno, Serge Volkoff nd ll members of he DARES "Gesion des Ages" sirring commiee for helpful commens nd suggesions. We lso hnk Andre Bssnin Giorgio Brunello nd pricipns o he EU Commission-JRC-CRELL conference on "Cch he Trin: Skills, Educion nd Jobs", Brussels, 2011 for useful commens. All remining errors re ours. We grefully cknowledge finncil suppor from DARES (Gesion des Ages progrm) nd from he French reserch gency (Agence Nionle de l Recherche) Grn n ANR-08-JCJC

2 1. Inroducion In mos Europen counries, populion hs been geing quickly in recen yers nd his rend is no expeced o rever in he ner fuure. A direc consequence of his hs been he increse in he rio of reirees o working populion, which hs genered in urn growing budge unblnces in he pension sysems. In order o reduce he resuling deficis, mny governmens hve incresed he legl ge of reiremen, hoping h his would decrese he reiree-o-working-populion rio. The success of such policy crucilly depends of course on wheher older workers re ble o find job or les sy in employmen (see Boldrin e l, 1999). So, i rises he issue of he demnd for lbour ddressed by firms o older workers. There is evidence in he lierure h he demnd for older workers hs been negively ffeced by he rpid developmen of informion nd communicion echnologies (ICT) nd of innovive work prcices in he ps decdes (see Auber e l, 2006, Beckmnn, 2007 nd Ronningen, 2007). Underlying his process is he fc h ICT ccelere skill obsolescence. Given h older workers hve compleed heir educion less recenly hn younger ones, hey re more ffeced by he loss of compeence. In his conex, coninuous rining becomes key policy insrumen o foser he employbiliy of older workers. The quesion we ckle in his pper is: how efficien is coninuous rining in improving he employmen prospecs of older workers in n environmen chrcerised by he developmen of new echnologies nd innovive work prcices? In order o nswer his quesion, we firs esime wge bill shre equions for differen ge groups. In order o conrol for unobserved heerogeneiy nd poenil reverse cusliy we esime long difference equions in which he chnge in he wge bill shre of ech ge group is funcion of he chnge in ICT nd innovive work prcices lgged one period nd rining lgged one period. Consisen wih wh is found in he lierure, we find h doping new echnologies nd innovive work prcices negively ffecs he wge bill shre of older workers. In conrs, rining older workers more hn verge increses heir shre in he wge bill in he nex period. So, rining conribues o offse he negive impc of ICT nd innovive work prcices. However, i does no reduce he ge bis ssocied wih hese innovive devices: he inercion erms beween rining nd ICT/innovive work prcices re eiher insignificn or negive. As second sep, we esime he impc of ICT, innovive work prcices nd rining on employmen flows by ge group in he nex period. We ge similr resuls o hose obined wih wge bill shres. Innovive devices 2

3 negively ffec older workers wih respec o oher ge groups eiher becuse hey increse hirings in smller proporion or becuse hey rise seprions more hn verge. In conrs, rining proecs older workers by reducing inflows of compeing ge groups. Overll, rining ppers o hve posiive impc on he employbiliy of older workers, bu i offers limied prospecs o dmpen he ge bis ssocied wih new echnologies nd innovive work prcices. Our pper conribues o he now vs lierure on ge bised echnicl chnge. The ide h echnologicl nd orgnisionl chnges negively ffec older workers hs been esed in vrious wys in he lierure. A firs srnd of ppers invesiges wheher ge hs negive impc on compuer use. On UK d Borghns nd Ter Weel (2002) find no evidence of such phenomenon. In conrs, Friedberg (2003) finds pril evidence of skills obsolescence in he USA, wih echnologicl chnge in worker's environmen hving negive impc on compuer use, bu only for workers close o reiremen. For Germny, Schleife (2006) finds srong nd negive correlion beween workers' ge nd compuer use. Similr resuls re found for he Neherlnds by Koning nd Gelderblom (2006). However, hese sudies re flwed by selecion bis. If workers who re less ble o dp o new echnologies nd innovive work prcices hve lredy reired or been lid-off, he effec of ge will be underesimed when looking how i correles wih compuer use. A second empiricl sregy hs herefore consised in esiming he impc of compuer use on reiremen decisions. On U.S. d Brel nd Sichermn (1993) show h workers in indusries wih higher re of echnologicl chnge end o reire ler. However, unexpeced chnges in he re of echnologicl chnge induce workers o reire erlier. Similr resuls re obined by Hegelnd e l (2007) for Norwy. A ls srnd of ppers hve ken differen view nd invesiged he impc of he inroducion of ICT nd innovive work prcices on firm's lbour demnd for older workers (Auber e l, 2006, Beckmnn, 2007, Ronningen, 2007). They ll find h he inroducion of innovive devices negively ffecs he wge bill shre of older workers. Our pper uses he sme mehodology. We lso find evidence of ge bised echnicl nd orgnisionl chnge nd exend he nlysis o consider he poenil role of rining in his djusmen. Our work lso conribues o he lierure on he impc of rining on he employbiliy of older workers. No much hs been done so fr on his issue. Using subjecive d on job securiy, Bssnini (2006) provides evidence h rining ken wih he previous employer hs posiive impc on he perceived job securiy of older workers. Schleife (2008) uses 3

4 more objecive mesure of employbiliy nd shows h he proporion of older workers receiving IT rining is posiively correled wih heir shre in employmen hree yers ler. Similr resuls re found by Behghel e l (2010). Similrly, Picchio nd Vn Ours (2011) find h older workers who receive rining re more likely o remin employed. The quesion we sk in his pper is: is his effec of rining srong enough o dmpen he ge bis ssocied wih he inroducion of ICT nd innovive work prcices? For Germny, Schleife (2008) finds h he posiive correlion beween IT rining provided o older workers nd heir shre in employmen is sronges in IT-inensive indusries wheres i is insignificn in less IT-inensive ones. Song (2009) suggess h rining could cully hrm older workers in conex of rpid developmen of ICT if i is firm specific. On CPS d he finds h he probbiliy of displcemen by posiion boliion increses wih ge, ICT use wihin n occupion/indusry nd wih he provision of specific rining by he employer. Bsed on hese resuls, he conjecures h firm specific rining my undermine job securiy of older workers in conex of rpid echnologicl chnges. The reson for his would be h echnologicl chnge deprecies he exising sock of firm-specific humn cpil hus leding firms o dismiss workers becuse hey find i unprofible o rerin hem. We es wheher he employmen prospecs of older workers re beer or worse when he inroducion of innovive devices is combined wih rining. We find h lhough rining increses he shre of older workers in employmen nd reduces heir urnover i is no srong enough o dmpen he ge bis ssocied wih ICT nd innovive work prcices. The lyou of he res of he pper is s follows. Secion 1 presens he economeric model. Secion 2 describes he d. Secion 3 repors he resuls nd Secion 4 concludes. 2. The economeric model In order o sudy he relionships beween rining nd he wge bill shres of he vrious ge groups in innovive firms, we use clssicl lbour demnd frmework. As is sndrd in he lierure, we ssume h he cos funcion is resriced rnslog (see for exmple Croli nd Vn Reenen, 2001). 2.1 Wge bill shres Since we re ineresed in he join effecs of rining nd innovion on he ge srucure of he workforce, we ssume h he only vrible fcors re he differen ypes of lbour s chrcerised by heir ge nd indexed by. Correspondingly, we ssume h cpil is 4

5 "qusi-fixed" fcor which vries only in he long run nd cn herefore be considered s exogenous in he shor run. Under hese ssumpions, he wge bill shres of he vrious ge groups re s follows see Auber e l (2006): S VA ' ln( VA) ' ln( W' ) i K ln( K) i TECH.ln( TECH ) i HK.ln( HK) i 1... A (1) i Z. Z i where S i,, denoes he wge bill shre of ge group in firm i de, K he sock of physicl cpil, VA he vlue-dded of he firm, vecor of indusry nd size dummies, nd W ' he hourly wge of ge group, Z i n error erm. We ssume h he sock of cpil of he firm lso encompsses echnologicl cpil (TECH) nd humn cpil (HK). TECH cpures he use of informion nd communicion echnologies nd/or innovive work prcices nd HK cpures he sock of humn cpil poenilly specific o ech ge group used in he producion process. The ol number of ge groups is A. Since we consider he sysem of wge bill shre equions for ll ge groups, we need o plce ddiionl resricions on he prmeers in order o mke sure h ll shres sum up o 1. Symmery implies h:, ' ', nd homogeneiy implies h: A 1 A 1 nd 0 u U u 1,..., A; VA; K; TECH; HK Z. 1, u ; Given h he wge bill shres of he vrious ge groups sum up o 1, one of he equions becomes redundn. So, we esime he sysem for ll ge cegories bu he firs one. The model becomes: S VA ln( VA) ' ' 2... A i Z ln( W. Z i ' / W ) 1 i K ln( K) 2... A i TECH ln( TECH ) i HK.ln( HK) i (2) The younges ge group (indexed by 1) is ken s he reference in order o compue relive wges ln( W W1 ) ' / i nd is herefore elimined from he equion sysem. This ge group 5

6 corresponds o workers ged 20 o 29 yers old (see Secion 3). A firs problem rised by equions (2) is h of reverse cusliy. The correlion we esime my indeed cpure he impc of he ge srucure of he workforce on rining rher hn he opposie. This problem rises in priculr if he ge srucure is persisen over ime which is likely o be he cse. 1 In order o overcome his problem, we esime our model in long differences where ps rining (i.e. he chnge in he sock of humn cpil beween -1 nd ) nd innovion (i.e. he chnge in he sock of echnologicl nd orgnisionl cpil) ffec he subsequen chnge in he ge srucure of he workforce (beween nd +1), conrolling for is iniil vlue. 2 This yields our esimed specificion: S 1 VA ' ' 2... A ln( VA) i ln( W P ' ' 1... A ' / W ) 1 ', 1 i K X ln( K). X i INNOV INNOV 2... A i TRAIN. TRAIN i (3) where S 1 is he chnge in he wge bill shre of he vrious ge groups, ln(k) i he, chnge in he log of he physicl cpil sock, ln(va) i he chnge in he log of vluedded, ln( W ' / W1 ) i he chnge in relive wges. 1 P is he ge srucure of he workforce before he inroducion of ICT nd innovive work prcices 3 nd X i is vecor of conrols including size nd indusry dummies. INNOV i cpures he inroducion of informion nd communicion echnologies nd/or innovive work prcices nd is proxy of ln(tech ). Similrly, he chnge in he sock of humn cpil ln(kh ) is proxied by coninuous rining (TRAIN i ). Firms' invesmens in rining re indeed flow which incremens he sock of humn cpil. 4 1 In order o highligh his poin, le's consider he exreme cse in which here is no enry nor exi beween he end of he 1980s nd 1998 (he yer h we consider see below).the ge srucure of he workforce in 1998 would hen be idenicl o h of 1988 wih every employee being 10 yers older. The heory of humn cpil ccumulion over he life cycle (Ben Porh, 1967) s well s empiricl evidence sugges h middle-ged workers receive disproporione moun of rining. So, firms in which lrge proporion of employees is ged 30 o 50 yers old in 1988 will mssively inves in rining nd will mechniclly hve workforce ged 40 o 60 yers old in This would resul in posiive correlion beween rining in 1988 nd he proporion of workers ged 40 o 60 in he workforce in Bu his correlion would no be due o he cusl effec of rining on minining senior workers in employmen. 2 A poenil drwbck of his mehod is h if new ICT or innovive work prcices hve been inroduced (beween nd +1), hey do no show up in our d which my led us o consider s non innovive firms h will become so few yers ler. Noe however h his should bis our resuls owrds finding no impc of ICT nd innovive work prcices. 3 More specificlly, i is he shre of he vrious ge groups in he number of dys worked s of We inroduce ime subscrips, +1 nd -1 o mke cler h vribles re mesured over differen periods. However, he inroducion of ICT nd innovive work prcices is only observed over one period; ech firm 6

7 This specificion ims sudying he impc of rining invesmens which my be specific o he vrious ge groups on he employmen prospecs of older workers nd he role he former my ply in miiging he effecs of innovion. Clerly, even hough reverse cusliy problems re ken ino ccoun nd severl confounding fcors re conrolled for, cusl inerpreion of he esimes sill relies upon he rgubly srong ssumpion h rining nd innovions re exogenous o fuure chnges in he srucure of he workforce. This ssumpion is common in he lierure on echnicl nd orgnizionl chnge, given he lck of plusible insrumens. I mus however be kep in mind. In our d he inroducion of ICT nd/or innovive work prcices ( INNOV ) is mesured beween he beginning of 1995 nd he end of In order o miige he reverse cusliy issue, we consider chnges in he wge bill shres of he vrious ge groups ( S 1) over Our rining mesure is verged over nd we conrol for he ge srucure of he workforce s of 1994, i.e. before he inroducion of ny innovive device. A problem wih equions (3) is h he error erms i my be correled cross ge groups wihin given firm. So, in order o ge n efficien esimor of he sndrd errors of he vrious coefficiens, we need o ke ino ccoun he shpe of he vrince-covrince mrix 2,..., i, i A, i. We do his by esiming SUR model by join generlised les squres (JGLS). When he explnory vribles re he sme in ll equions - s is he cse here - his mouns o esiming he sysem by OLS equion by equion. 5 i, 2.2 Worker flows Anoher wy o ge he role of innovion nd rining in shping he employmen prospecs of older workers is o esime direcly worker flows boh ino nd ou of firms s funcion of ps dopion of ICT nd/or innovive work prcices nd ps rining invesmens. This llows us o idenify he mechnisms hrough which innovion nd rining ffec lbour demnd: is he min effec on hirings or lernively on seprions? We denoe N i,, he number of workers ged who re hired yer in firm i nd N, i, he number of workers of he sme ge group who leve he firm in he course of he yer. eners he esimion only once (wih some vribles in 3-yer difference). 5 See, e.g., Theorem 7.6 in Wooldridge,

8 We define he shre of newly hired workers ged in firm i de s N P, nd N he shre of workers leving he firm s: N P,. These shres re verged over he N period We ssume h P i,, nd P i,, cn be wrien s: VA P INNOV TRAIN INNOV 1 TRAIN 1 K ln( ) ln( VA) ' ln( W 2... A 2... A / W ) 1. P 1 (4) nd K M. M VA P INNOV TRAIN INNOV 1 TRAIN 1 K ln( ) ln( VA) ' ln( W 2... A 2... A / W ) 1. P 1 M K. M (5) INNOV -1 denoes our mesure of innovion nd TRAIN -1, he invesmen in rining which re boh mesured over { ln( W / W1) ; ln( K ) i, ; ln( VA ) i, } is vecor of demnd fcors (chnge in relive wges, in physicl cpil nd in vlue-dded beween 1998 nd 2000) specific o firm i. P 1 is he shre of ge group in he workforce before, he inroducion of innovion (i.e. s of 1994) nd M i is vecor of conrols idenicl o X i in equion (3) bu including yer fixed effecs for 1999 nd nd re 1 1 sochsic error erms. The min dvnge of his liner model is h i llows us o esime he shre of inflows nd ouflows for ll ge groups simulneously by using he SUR mehod see secion 2.1 bove. In urn, his llows us o ke ino ccoun he poenil correlion beween hirings nd seprions cross vrious ge groups. Given h we re ineresed in he impc of innovion nd rining upon hirings nd seprions of older workers relive o younger ones, we decompose nd INNOV TRAIN (resp. INNOV nd TRAIN ) ino wo differen erms: (resp. ) is componen h 8

9 is common o ll ge groups nd represens he verge impc of innovion or rining on hiring (resp. on seprions) nd (resp. ) is componen which is ge specific: nd In order o be ble o idenify he model, we consrin he (resp. zero. As consequence: The sme holds for seprions. ) o dd up o e (6) A A 3. The d The d h we use come from severl sources. Informion on ICT nd innovive work prcices comes from he COI survey (Chngemens Orgnisionnels e Informision) crried ou by SESSI 6 he end of 1997 nd covering 4,283 firms wih more hn 20 workers in he mnufcuring secor. 7 In order o ge informion on wges nd on he ge srucure of he workforce, we mched COI wih mndory socil securiy repors: he DADS files (Déclrions Annuelles des Données Sociles). The DADS is n exhusive dse providing informion on firm size nd indusry on yerly bsis since Moreover, for ech employee, he DADS hs informion on he number of hours nd dys worked during he yer, s well s on wges, ge nd occupion. Informion on physicl cpil nd vluedded comes from he BRN (Bénéfices Réels e Normux) which consiss of firms' blnce shees colleced by he x dminisrion. I conins more hn 600,000 firms from he prive non-finncil secor nd covers bou 80% of ol sles in he French economy. Trining d re rerieved from he "24-83" fiscl records. They conin informion on he number of workers receiving rining nd he volume of rining hours broken down by gender, ge nd occupion for every yer. The "24-83" records re exhusive for ll French firms wih more hn 10 employees, bu only smple is vilble for reserch. This smple conins 15 o 20,000 firms every yer bu lrger smple (30 o 40,000 firms) is vilble every hree yers. 6 French Minisry of Indusry. 7 Complemenry surveys hve been conduced in he food-processing, rde nd service secors, bu he number of firms covered by ech of hem is much smller hn in he mnufcuring secor (resp. 970, 648 nd 1482). Moreover, he quesions sked being somewh differen, we will focus exclusively on he mnufcuring secor. 9

10 Mching he differen dbses leves us wih smple of 2,352 firms s compred o 4,283 in he originl COI dse. This is due o he fc h we only keep hose firms for which we hve d on rining while he "24-83" records re no exhusive. The firms h we lose re essenilly smll ones since he firs decile of he size disribuion hs less hn 26 workers in he originl dse s compred o 34 in ours. Similrly, he medin size of firms in our smple is 150 workers s compred o 86 in he COI dbse nd he verge size is 552 s compred o 429 in COI. Noneheless, he disribuion of firms cross indusries is very similr in boh dses: bou hlf of he firms belong o he inermedie good secor % in our smple s compred o 45.2% in COI (see Appendix Tble A.1) - nd lmos one fourh is in he durble good secor 23.6% dns COI s compred o 23.4% in our smple. The only noble difference lies in he shre of firms in he moor vehicle mnufcuring indusry - wih 4.6% in our smple s compred o 3.7% in COI nd o smller exen in he non-durble good secor 21.3% in our dbse s compred o 25.1% in COI. Bu overll, differences beween boh dses remin very limied. As regrds worker flows, we llow djusmen o ke ime nd hus pool our d over We joinly esime employmen flows for ll groups in ech firm. So we use smple of 6,824 firms * yer; for ech of hese, we mesure inflows nd ouflows by ge groups. The ge groups h we consider re 20 o 29, 30 o 39, 40 o 49 nd 50 o 59 yers old. Employees ged 60 nd more re excluded given h he legl ge of reiremen ws 60 during he period under sudy. Using he informion vilble in he COI dse, we define 4 indicors of inroducion of new echnologies nd innovive work prcices. Following Biscourp e l. (2002), our firs indicor is Inerne which kes vlue 1 if he firm uses his echnology eiher for emiling or o diffuse or gher informion; i kes vlue 0 oherwise. We ssume h Inerne being is very sr in Frnce in he mid-1990s, he re of use declred in 1997 is equivlen o n dopion re. Our second indicor is D_COMP, which cpures he inroducion of neworkinerconneced compuers in he producion deprmen. D_COMP is equl o 1 if he firm hs inroduced his ype of equipmen beween 1995 nd 1997; 0 oherwise. The COI survey lso hs informion on he inroducion of innovive work prcices. A firs indicor cpures he reducion in hierrchicl lyers wihin firms: D_HIERAR is equl o 1 if he number of hierrchicl lyers ws smller in 1997 hn in 1995; 0 oherwise. A second indicor cpures he increse in he moun of responsibiliy wrded o operors over he period: D_RESP vries beween -10 nd +10 ccording o he number of new responsibiliies 10

11 operors hve been wrded beween 1995 nd As regrds rining, he "24-83" records provide informion on he relive ccess re o rining for hree differen ge groups: younger hn 25 yers old, 25 o 44 yers old nd 45 nd older. More precisely, for ech of he bove ge groups, we build vrible denoed TRAIN_X which is equl o he re of rining in ge group X divided by he verge re of rining in he workforce. 9 This vrible cpures he relive re of rining cross he vrious ge groups. 10 To he exen h our d come from differen sources, he ge groups used o build he relive rining res younger hn 25 yers old, yers old nd 45 yers old nd bove do no excly correspond o he ones we use o cpure he chnge in he ge srucure of he workforce. For he ske of coherence wih our echnicl nd orgnisionl chnge indicors, he rining vribles re verged over see descripive sisics in Appendix Tbles A2 o A5. 4. Resuls 4.1 Innovion, rining nd chnge in he ge srucure of he workforce Overll effecs As firs sep, we esime he impc of he dopion of ICT, innovive work prcices nd rining on he subsequen chnge in he ge srucure of he workforce, conrolling for he iniil ge srucure o he exen h i generes mechnicl chnge in he wge bill shres of he vrious ge groups (see Tble 1). Consisen o wh is found in he lierure, ICT nd innovive work prcices pper o be ge bised: boh he inroducion of he Inerne nd he dopion of nework-inerconneced compuers re correled wih n increse in he shre of workers ged in he wge bill, wheres hey re ssocied wih decrese in he shre of workers ged The 8 The quesion is phrsed s follows: "In he workshops of your firm, who is eniled o: (1) fine-une he pprels (2) opere bsic minennce (3) lloce sks mong operors (4) conrol he quliy of supplies (5) conrol he quliy of he produc (6) pricipe o performnce improvemen (7) pricipe o projecmngemen ems (8) sop he producion process in cse of inciden (9) mke firs dignosis in cse of inciden (10) sr producion gin when sopped becuse of inciden". For ech quesion, he survey offers hree possible nswers: "hierrchy, operor, specilis". The quesions re sked for 1994 nd We give vlue 1 o ech nswer involving n operor so h he ggrege responsibiliy indicor vries beween 0 nd 10. Our D_RESP vrible is hen defined s he difference beween he ggrege indicors for 1997 nd TRAIN_X = [(number of employees from ge group X receiving rining) / number of employees in ge group X)] / [(ol number of rinees in he firm / ol number of employees in he firm)]. 10 The relive res of rining for he hree ge groups re no sricly colliner s long s he ge groups do no hve he sme size. 11

12 inroducion of innovive work prcices lso ffecs he wge bill shre of he vrious ge groups. As for ICT, n increse in he moun of responsibiliy wrded o operors is ssocied wih n increse in he shre of younger workers (30 o 39) in he wge bill nd wih reducion in he shre of older workers (ged 50-59). Ineresingly, reducion in he number of hierrchicl lyers seems o hve he opposie effec: i is correled wih n increse in he shre of workers ged nd wih reducion in he shre of younger employees (ged 30-39). This resul suggess h he decenrlision of he producion process ssocied wih he reducion in he number of hierrchicl lyers my genere some form of reurn o experience which posiively ffecs he employmen nd/or wge prospecs of older workers. As regrds he impc of rining, he resuls presened in Tble 1 sugges h rining of older workers (TRAIN_3) is ssocied wih subsequen increse in he shre of he wge bill ccruing o hem. The higher he relive rining re of workers ged 45 nd bove s compred o verge rining in he firm in , he greer he increse in heir wge bill shre over , ll oher hings equl. In conrs, rining of older workers hs negive impc on he chnge in he wge bill shre of workers ged Ineresingly, here is no similr effec of he relive rining res of younger ge groups: TRAIN_1 nd TRAIN_2 re no significnly correled o chnges in he wge bill shre of he corresponding ge groups. The model we hve esimed so fr ws derived from rnslog cos funcion so h we hve focused on chnges in he wge bill shres. However, one my wonder wheher he observed correlions re due o chnges in he shre of he vrious ge groups in employmen or, lernively, o chnges in relive wges. In order o ckle his issue, we re-esime equion (3) on he shres of he 4 ge groups in employmen more precisely, in he number of dys worked. The corresponding resuls re presened in Tble 2. The coefficiens on he innovion vribles re close o hose obined in Tble 1, bu some of hem re less precisely esimed. The Inerne is sill bised gins older workers bu he posiive correlion wih he shre of workers ged in employmen is no significn. Symmericlly, he inroducion of nework-inerconneced compuers nd he increse in he moun of responsibiliy wrded o operors re sill posiively ssocied wih he shre of younger workers (ged 30-39) bu he negive correlion wih he shre of older workers is no longer significn. By conrs, he decrese in he number of hierrchicl lyers hs he sme effec on employmen s on wge bill shres: i is posiive for older workers nd 12

13 negive for younger ones. As regrds rining, i does no ffec he ge srucure of employmen when focused on young nd middle-ged workers. As ws he cse for he wge bill shres, he only significn resuls re for he relive rining re of older workers which negively ffecs he shre of workers ged in employmen bu posiively ffecs h of workers ged 40-49, while i hs no effec on he oldes ge group wheres he opposie held in Tble 1. Overll, he resuls we obined on wge bill shres seem o be lrgely driven by effecs on he ge srucure of employmen, bu in some cses relive wges ply role oo. Regrding he inroducion of nework-inerconneced compuers nd he increse in he moun of responsibiliy wrded o operors, he negive correlion wih he wge bill shre of older workers evidenced in Tble 1 seems o be mosly due o decrese in heir relive wge, rher hn o decrese in heir shre in employmen. 11 Similrly, he posiive impc of he relive re of rining of older workers on he subsequen chnge in heir wge bill shre would essenilly go hrough n impc on he relive wges of older workers, rher hn n increse in heir shre in ol employmen. Overll, our resuls sugges h echnologicl nd orgnisionl innovions re bised gins older workers nd in fvour of younger ones. In conrs, ccess o rining for workers ged 45 nd more seems o hve posiive impc on heir employmen nd wge prospecs: on heir shre in employmen for hose ged 40 o 49 nd on heir relive wge for he oldes group (ged 50-59). Innovion, rining nd chnge in he ge srucure wihin occupions The relionships beween innovion, rining nd chnge in he ge srucure of he workforce re confirmed when re-esiming our model wihin occupionl cegories (see Tble 3). Regrding innovion, he ge bis is priculrly srong wihin he mngeril group. The Inerne posiively ffecs he wge bill shre of mngers ged while i is negively correled wih h of older mngers. Similrly, he inroducion of nework-inerconneced compuers nd he increse in he moun of responsibiliy wrded o operors pper o be negively correled wih he wge bill shre of older mngers. These effecs re fr less srk for clerks since only he Inerne hs ny significn effec. However, he correlion 11 For insnce, he coefficien on he inroducion of nework-inerconneced compuers is -.44 (significn he 10% level) when considering he wge bill shre of workers ged 50 o 59 s he dependen vrible, nd only -.16 (no sisiclly significn) when considering heir shre in employmen. Noe however h sndrd errors re lrge, so h he difference in poin esimes is only suggesive, bu no sisiclly significn. 13

14 beween is dopion nd he wge bill shre of he vrious ge groups ppers o be negive for he yer olds which does no suppor he ge bis hypohesis. In conrs, he dopion of he Inerne is ssocied wih decrese in he proporion of older blue-collrs. Ineresingly, he posiive correlion beween he reducion in he number of hierrchicl lyers nd he wge bill shre of older workers found in Tble 1 seems o be lmos enirely due o mngers. This "pro-ge" bis does no exis for clerks nd even seems o chnge sign for blue-collrs: he flening of he hierrchicl srucure is indeed ssocied wih n increse in he shre of he younges ge group (20-29 yers old) he expense of he yer olds. This resul suggess h if experience my become n sse when he hierrchicl srucure flens, his only occurs for he mos highly skilled workers. Regrding rining, he relionship beween he relive rining re of older workers nd heir shre in he wge bill is less srk wihin occupions. This my be due o he shorcomings of our d. Idelly, we would hve correled he relive re of rining of he vrious ge groups of mngers wih he chnge in he ge srucure of he workforce mong mngers; nd similrly for clerks nd blue-collrs. However, our rining d do no include informion on rining res by ge nd occupion. So, we cn only correle he relive rining re in ech ge group s compued for ll occupions - wih he chnge in he ge srucure of he workforce wihin our hree occupionl cegories. This imperfec correspondence my resul in n enuion bis. In our view, such n exercise is however ineresing in order o deec which occupions re mos sensiive o chnges in relive rining res. As indiced by resuls in Tble 3, he relive rining re of workers ged 45 nd bove is sill posiively correled o n increse in heir wge bill shre, bu he coefficien is only significn for clerks (nd he 10% level). 12 However, rining of older workers is persisenly ssocied wih decrese in he wge bill shre of younger ge groups: his is he cse for workers ged in mngeril occupions nd for workers ged mong blue-collrs. Overll, greer ccess o rining for older workers beween 1995 nd 1997 is ssocied wih chnge in he ge srucure of he workforce he expense of younger workers, nd in fvour of older ones in he nex period ( ). A similr resul is obined for middle-ged workers (25-44 yers old): mong clerks, he relive rining re of workers ged is negively correled o he chnge in he wge bill shre of he younges ge group (20-29 yers old) nd posiively correled wih he shre of workers who re direcly ffeced by he rining ( les for hose ged 40-49). Moreover, 12 The fc h he esimes re less ofen sisiclly significn my be due in principle o reduced precision his disggreged level. However, poin esimes lso end o be lower. 14

15 rining of middle-ged clerks is negively ssocied wih he chnge in he wge bill shre of he oldes ge group wihin he clerk cegory (50-59 yers old). These resuls re no surprising given he definiion of our rining indicors: if middle-ged workers hve been rined more hn verge over he period, his mens h older nd/or younger workers hve been rined less. So, he decrese in heir wge bill shre over he nex period jus confirms he exisence of relionship beween rining nd chnge in he ge srucure of he workforce in fvour of hose ge groups who hve been direcly ffeced by rining. However, his resul does no hold for blue-collrs: rining of workers ged is indeed ssocied wih n increse in he wge bill shre of older workers (ged 50-59) nd wih decrese in h of workers ged Finlly, he relive rining re of he younges ge group (less hn 25 yers old) is no significnly correled o ny chnge in he ge srucure of he workforce. Overll, he ge bis of ICT nd innovive work prcices seems o be priculrly srong mong mngers. Trining of older workers posiively ffecs heir wge nd/or employmen prospecs, bu he effec is significn only mong clerks. Trining, innovion nd he ge bis of ICT nd innovive work prcices One imporn issue we wn o ckle here is wheher rining my miige he ge bis induced by ICT nd innovive work prcices. In order o nswer his quesion, we esime specificion, similr o h used in Tble 1, in which we inerc he relive re of rining of older workers wih our innovion vribles see Tble 4. The coefficiens on he inercion erms re no very encourging. While he Inerne does no seem o hve much effec on he wge bill shres of he vrious ge groups per se, he correlion becomes posiive for he younges ge group (20-29 yers old) nd negive for workers ged when inroduced in firms which inves in rining in disproporione wy for older workers. Similrly, while he flening of he hierrchicl srucure seems o hve negive effec on workers in heir 30s per se, his effec vnishes in firms where older workers receive more rining hn verge. The only cse in which rining of older workers seems o dmpen he ge bis due o innovion is for responsibiliies wrded o operors: while he direc effec of his new orgnisionl prcice is negive for he wge bill shre of he oldes ge group, i is srongly enued when older workers hve been rined more hn verge in he previous period. Overll, echnologicl nd orgnisionl innovions on he one hnd nd rining on he 15

16 oher hnd seem o hve opposie effecs on he ge srucure of he workforce excep for he flening of he hierrchicl srucure. However, our resuls do no provide evidence h rining would reduce he ge bis due o he inroducion of ICT nd innovive work prcices. 4.2 Innovion, rining nd employmen flows by ge group The resuls presened in Tble 5 nlyse inflows nd ouflows of workers boh on verge nd for ech ge group. These flows rele o ll ypes of lbour conrcs, be hey permnen or emporry. The impc of ICT nd innovive work prcices on he ge srucure of employmen inflows nd ouflows ppers o be quie vried ccording o he ype of innovion under sudy. The dopion of he Inerne increses hirings wihou ffecing seprions, wheres he inroducion of nework-inerconneced compuers nd he reducion in he number of hierrchicl lyers do no seem o ffec he ggrege level of inflows nd ouflows. As regrds he increse in he moun of responsibiliy wrded o operors, i conribues o reduce urnover s whole given is negive effec on boh hirings nd seprions. The sme holds for rining of younger nd middle-ged workers which is negively correled boh wih inflows nd ouflows. As regrds he relive re of rining of older workers, i is lso ssocied wih reducion in inflows, bu does no seem o be significnly correled wih ouflows. Coming now o he differenil impc on he inflows nd ouflows of he vrious ge groups, younger workers pper o be posiively ffeced by he Inerne: i increses hirings of workers ged more hn verge while reducing heir ouflow. The opposie holds for older ge groups since he Inerne is ssocied wih n increse in ouflows (wih no increse in inflows) for workers ged nd o reducion in relive hirings (wih no impc on seprions) for workers ged The inroducion of nework-inerconneced compuers reduces hirings in significn wy in he younges ge group, bu i lso reduces seprions. The opposie holds for workers ged for whom ouflows increse when nework-inerconneced compuers re inroduced. The reducion in he number of hierrchicl lyers increses inflows of workers ged nd reduces hose of workers ged wheres i does no seem o ffec he ge srucure of ouflows. In conrs, incresing responsibiliy of operors hs no impc on he ge srucure of inflows, wheres 16

17 i hs cler negive effec on older workers s fr s seprions re concerned: D_RESP reduces ouflows less hn verge for workers ged nd while i reduces seprions more hn verge in he younges ge group. As regrds rining invesmens mde by firms, hey srongly ffec hirings nd seprions of he ge groups which re direcly ffeced by he rining. The relive re of rining of workers ged 25 yers old nd below reduces ouflows more hn verge in he corresponding ge group (i.e. workers ged 20-29), wihou ffecing inflows. In prllel i negively ffecs he oldes workers by reducing heir inflows more hn heir ouflows. Regrding rining of middle-ged workers (25-44 yers old) i reduces ouflows in he ge group more hn verge s well s he re of urnover of workers ged In conrs, i negively ffecs older workers s compred o younger ge groups, o he exen h i reduces heir ouflows much less hn for middle-ged workers. Finlly, rining of older workers ends o proec hem. I reduces inflows of ll cegories of workers bu his reducion is smller hn verge for workers ged 50-59, wheres i is significnly lrger hn verge for compeing ge groups (in priculr hose ged 40-49). As consequence, rining older workers more hn verge hs posiive impc on heir relive shre in employmen. Overll, i seems h lrge pr of he effec of innovion nd rining on workers' flows by ge group goes hrough urnover. The dopion of nework-inerconneced compuers reduces he re of urnover mong he younges ge group. Trining of middle-ged nd older workers conribues o he reducion of he re of urnover mong he yer old group. Moreover, when innovions nd rining only ffec hirings or seprions, our resuls sugges h ICT nd innovive work prcices hve negive impc on older workers s compred o oher ge groups. This occurs eiher becuse innovions rise he inflow of older workers less hn verge (e.g. Inerne for he 40-49) or becuse hey increse heir ouflows relive o oher ge groups (e.g. nework-inerconneced compuers nd increse in he responsibiliy of operors for employees ged 50 nd bove). In conrs, rining seems o proec he cegories of workers who re direcly ffeced, eiher by incresing heir hirings s compred o he oher ge groups s is he cse for older workers or by reducing heir seprions - s is he cse for he younges group nd for middle-ged workers. All in ll, he nlysis of employmen flows confirms he resuls obined when esiming he wge bill shre model: ICT nd innovive work prcices negively ffec he 17

18 employmen prospecs of older workers, wheres concenring rining invesmens on hem helps sbilise heir shre in he wge bill in he nex period. 5. Conclusion Our reserch confirms h ICT nd innovive work prcices re bised gins older workers. This is he wy we inerpre he negive correlion h we find beween echnologicl nd orgnisionl innovions on he one hnd nd subsequen chnge in he wge bill shre of older workers on he oher hnd. This resuls holds wih vrious mesures of echnologicl nd orgnisionl chnge, nmely he inroducion of he Inerne, he inroducion of nework-inerconneced compuers nd he increse in he moun of responsibiliy wrded o operors: ll hree innovive devices increse he shre of workers in heir 30s nd reduce h of older workers in he wge bill nd, o smller exen, in employmen. Ineresingly, in conrs, he flening of he hierrchicl srucure ppers o be fvourble o older workers nd correspondingly unfvourble o workers ged 30-39: i increses he shre of workers ged boh in he wge bill nd in employmen. One reson for his my be h ci knowledge plys n imporn role when flening he hierrchicl srucure. Skills cquired by older workers hrough lerning-by-doing re ll he more necessry o firms h hey incorpore n imporn pr of ci knowledge which is hrdly subsiuble. When his is he cse, older workers possess vluble sse which my enhnce heir employbiliy. When flening he hierrchicl srucure of he firm, ci knowledge held by workers is likely o become more imporn, in priculr s regrds communicion nd work orgnision. Older workers hen benefi from comprive dvnge which does no exis when echnologicl nd orgnisionl innovions genere greer knowledge codificion. Such mechnism could ccoun for he posiive impc of he reducion in hierrchicl lyers upon he employmen prospecs of older workers. Moreover, our resuls sugges h rining ends o proec older workers in erms of employmen nd/or ernings. The relive rining re of workers ged 45 nd bove is indeed ssocied wih n increse in heir shre in employmen (for hose ged 40-49) or in he wge bill (for he ge group). Thus doing, i conribues o offse he negive effecs of ICT nd innovive work prcices on older workers. However, le us underline h rining does no reduce he ge bis ssocied wih echnologicl nd/or orgnisionl innovions o he exen h he inercion erms beween innovions nd rining re eiher insignificn or negive in he models h we esime. So, lhough rining hs posiive 18

19 impc on employmen nd ernings of older workers, i offers only limied prospecs o enhnce heir employbiliy, in conex where echnologicl nd orgnisionl innovions end o develop. These resuls re obined by esiming chnges in he wge bill nd employmen shres of he vrious ge groups. We ge very similr perns when esiming employmen flows. Our resuls sugges h echnologicl nd orgnisionl innovions hve mosly negive effecs on older workers in relive erms, eiher becuse hey rise hirings less hn verge or becuse hey increse seprions in disproporione wy in he oldes ge group. In conrs, rining invesmens reduce urnover bu lso proec hose groups of workers who re direcly ffeced by he rining, eiher by incresing hirings s compred o oher ge groups s is he cse for older workers or by reducing seprions s hppens for younger or middle-ged workers. Our reserch suggess h policies iming incresing he employbiliy of older workers cnno enirely rely on rining in world where echnologicl nd orgnisionl innovions re expnding. More hs o be done in order o help older workers dp o he new communicion nd orgnisionl devices. One opion probbly consiss in wrding workers more ime o djus o he new producion mehods see Jolive (2003). This is of course chllenge in conex of incresing compeiion nd globlision of economic civiies. However, given he rhyhm which populion is geing in mos developed counries, his chllenge hs o be me in order o minin older workers in employmen. 19

20 References Auber Prick, Eve Croli nd Muriel Roger, 2006 " New Technologies, Orgnision nd Age: Firm-Level Evidence", Economic Journl, 116, pp Brel Ann nd Nchum Sichermn, 1993, "Technologicl Chnge nd Reiremen Decisions of Older Workers", Journl of Lbor Economics, 11(1), pp Bssnini Andre 2006, "Trining, wges nd employmen securiy: n empiricl nlysis on Europen d", Applied Economics Leers, 13(8), pp Beckmnn Michel, 2007, Age-bised echnologicl nd orgnizionl chnge : Firm-level evidence nd Mngemen Implicions, Discussion Pper n 05/07, Fculy of Business nd Economics, Universiy of Bsel. Behghel Luc, Eve Croli nd Muriel Roger "Dépr des rvilleurs âgés, formion coninue e chngemens echniques ou orgnisionnels", Trvil e Emplo vol. 121, n Jnvier-Mrs, pp , Ben Porh Yorm, 1967, "The Producion of Humn Cpil nd he Life Cycle of Ernings", Journl of Poliicl Economy, 75(4), pp Biscourp Pierre, Bruno Crepon, Thoms Heckel nd Nicols Riedinger, 2002, "How do firms respond o cheper compuers? Microeconomeric evidence for Frnce bsed on producion funcion pproch", Economie e Sisique n , pp Boldrin Michele, Jun Doldo, Jun Jimeno nd Frnco Percch 1999, "The Fuure of Pensions in Europe", Economic Policy, 14(29), pp Borghns Lex nd Bs Ter Weel, 2002, "Do Older Workers Hve More Trouble Using Compuer hn Younger Workers?", in A. de Grip, J. vn Loo nd K. Myhew eds: "The Economics of Skills Obsolescence", Reserch in Lbor Economics, vol. 21, pp Croli Eve nd John Vn Reenen, 2001, ''Skill bised orgnizionl chnge? Evidence from pnel of Briish nd French esblishmens'', The Qurerly Journl of Economics, 116(4), pp Friedberg Leor 2003, "The impc of Technologicl Chnge on Older Workers: Evidence from D on Compuer Use", Indusril nd Lbor Relions Review, 56(3), pp Hegelnd Torbjorn, Dg Ronningen nd Kjell Slvnes, 2007, "Adp or wihdrw? Evidence on echnologicl chnges nd erly reiremen using mched worker-firm d", Sisics Norwy, Reserch Deprmen Discussion Pper n 509. Jolive Annie, 2003, «The cluser of issues surrounding working ime, work orgnision nd job design», in M. Jepsen, D. Foden, M. Husebu (eds), A lifelong sregy for cive geing, ETUI, Brussels, pp de Koning Jp nd Arie Gelderblom, 2006, "ICT nd older workers: no unwrinkled relionship", Inernionl Journl of Mnpower, 27(5), pp Picchio Meo nd Jn Vn Ours, 2011, "Reining hrough Trining: Even for Older Workers", IZA Working Pper n Ronningen Dg, 2007, "Are echnologicl chnge nd orgnizionl chnge bised gins older workers? Firm-level Evidence", Sisics Norwy, Reserch Deprmen Discussion Pper n

21 Schleife Krin, 2006, "Compuer Use nd Employmen Sus of Older Workers An Anlysis bsed on Individul D", Lbour, 20(2), pp Schleife Krin, 2008, "IT Trining nd Employbiliy of Older Workers", ZEW Discussion Pper n Song Younghwn, 2009, "Trining, Technologicl Chnges nd Displcemen", Journl of Lbor Reserch, 30(3), pp Wooldridge Jeffrey, 2002, Economeric Anlysis of Cross Secion nd Pnel D MIT Press, Cmbrige. 21

22 Tble 1 : Innovion, rining nd chnge in he ge srucure of he workforce (coefficiens x100) Chnge in he wge bill shre Age Age Age Age Inerne ** *** (0.23) (0.26) (0.28) (0.27) Inroducion of nework-inerconneced * * compuers (D_COMP) (0.23) (0.26) (0.28) (0.27) Reducion in he number of hierrchicl ** ** lyers (D_HIERAR) (0.29) (0.33) (0.36) (0.34) Increse in he moun of responsibiliy *** * wrded o operors (D_RESP) (0.06) (0.06) (0.07) (0.07) Relive rining re of employees below yers old (TRAIN_1) (0.08) (0.09) (0.10) (0.09) Relive rining re of employees ged o 44 yers old (TRAIN_2) (0.22) (0.25) (0.27) (0.26) Relive rining re of employees ged *** *** yers old nd bove (TRAIN_3) (0.22) (0.24) (0.26) (0.25) Smple size: 2,352 Firms. Noe : 1. The relive rining re of ge group X is defined s he rining re in ge group X divided by he verge rining re in he firm's workforce. 2. The resuls in his ble re he oucomes of join esimes of wge bill shres for ll ge groups excep he younges one by join generlised les squres (JGLS). Bsic conrols include four size nd five indusry dummies s well s he chnge in relive wges, log vlue-dded nd log of physicl cpil. We lso conrol for verge rining expendiure beween 1995 nd 1997 nd for he ge srucure of he workforce s of Innovion nd rining vribles refer o he period. 3. The coefficiens for he younges ge group (20-29 yers old) re esimed using he following homogeneiy condiions : ec. 2029, D _ COMP 3039, D _ COMP 4049, D _ COMP 5059, D _ COMP 4. Esimed sndrd errors sympoiclly robus o heeroskedsiciy, re repored in prenheses. Esimes which re significn he 1 (resp. 5 nd 10)% level re indiced by *** (resp. ** nd *).

23 Tble 2 : Chnge in he ge srucure of he workforce, innovion nd rining, Employmen shres (coefficiens x100) Chnge in he shre of ech ge group in he number of dys worked Age Age Age Age Inerne *** (0.28) (0.27) (0.27) (0.24) Inroducion of nework-inerconneced * compuers (D_COMP) (0.28) (0.27) (0.27) (0.24) Reducion in he number of hierrchicl ** * lyers (D_HIERAR) (0.35) (0.34) (0.34) (0.31) Increse in he moun of responsibiliy ** wrded o operors (D_RESP) (0.07) (0.07) (0.07) (0.06) Relive rining re of employees below yers old (TRAIN_1) (0.10) (0.09) (0.09) (0.08) Relive rining re of employees ged o 44 yers old (TRAIN_2) (0.27) (0.26) (0.26) (0.24) Relive rining re of employees ged *** 0.69*** 0.35 yers old nd bove (TRAIN_3) (0.26) (0.25) (0.25) (0.23) Smple size: 2,352 Firms. Noe : 1 The relive rining re of ge group X is defined s he rining re in ge group X divided by he verge rining re in he firm's workforce. 2. The resuls in his ble re he oucomes of join esimes of wge bill shres for ll ge groups excep he younges one by join generlised les squres (JGLS). Bsic conrols include four size nd five indusry dummies s well s he chnge in relive wges, log vlue-dded nd log of physicl cpil. We lso conrol for verge rining expendiure beween 1995 nd 1997 nd for he ge srucure of he workforce s of Innovion nd rining vribles refer o he period. 3. The coefficiens for he younges ge group (20-29 yers old) re esimed using he following homogeneiy condiions : ec. 2029, D _ COMP 3039, D _ COMP 4049, D _ COMP 5059, D _ COMP 4. Esimed sndrd errors sympoiclly robus o heeroskedsiciy, re repored in prenheses. Esimes which re significn he 1 (resp. 5 nd 10)% level re indiced by *** (resp. ** nd *). 23

24 Tble 3 : Innovion, rining nd chnge in he ge srucure of he workforce, by occupion (coefficiens x100) Mngers nd echnicins (Chnge in he wge bill shre) Mngers Age Age Age Age Inerne ** * (0.10) (0.14) (0.20) (0.25) (0.25) Inroducion of nework-inerconneced ** compuers (D_COMP) (0.10) (0.14) (0.19) (0.24) (0.25) Reducion in he number of hierrchicl * ** lyers (D_HIERAR) (0.13) (0.18) (0.24) (0.30) (0.31) Increse in he moun of responsibiliy ** ** wrded o operors (D_RESP) (0.03) (0.04) (0.05) (0.06) (0.06) Relive rining re of employees below 25 yers old (TRAIN_1) (0.03) (0.05) (0.07) (0.08) (0.08) Relive rining re of employees ged 0.21** o 44 yers old (TRAIN_2) (0.10) (0.14) (0.19) (0.23) (0.24) Relive rining re of employees ged * yers old nd bove (TRAIN_3) (0.09) (0.13) (0.18) (0.23) (0.23) Clerks (Chnge in he wge bill shre) Inerne Inroducion of nework-inerconneced compuers (D_COMP) Reducion in he number of hierrchicl lyers (D_HIERAR) Increse in he moun of responsibiliy wrded o operors (D_RESP) Relive rining re of employees below 25 yers old (TRAIN_1) Relive rining re of employees ged 25 o 44 yers old (TRAIN_2) Relive rining re of employees ged 45 yers old nd bove (TRAIN_3) Clerks Age Age Age Age ** (0.06) (0.07) (0.09) (0.08) (0.07) (0.06) (0.07) (0.09) (0.08) (0.07) (0.07) (0.09) (0.11) (0.10) (0.09) (0.01) (0.02) (0.02) (0.02) (0.02) (0.02) (0.02) (0.03) (0.03) (0.02) * *** -0.17** (0.05) (0.07) (0.08) (0.08) (0.07) * (0.05) (0.07) (0.08) (0.08) (0.07) Blue-Collrs (Chnge in he wge bill shre) Blue-collrs Age Age Age Age Inerne * (0.10) (0.19) (0.19) (0.20) (0.16) Inroducion of nework-inerconneced compuers (D_COMP) (0.10) (0.18) (0.18) (0.19) (0.16) Reducion in he number of hierrchicl -0.21* 0.44* -0.42* lyers (D_HIERAR) (0.12) (0.23) (0.23) (0.25) (0.20) Increse in he moun of responsibiliy wrded o operors (D_RESP) (0.02) (0.05) (0.05) (0.05) (0.04) Relive rining re of employees below 25 yers old (TRAIN_1) (0.03) (0.06) (0.06) (0.07) (0.05) Relive rining re of employees ged -0.19** ** 0.32** 25 o 44 yers old (TRAIN_2) (0.09) (0.18) (0.18) (0.18) (0.15) Relive rining re of employees ged ** yers old nd bove (TRAIN_3) (0.09) (0.17) (0.17) (0.18) (0.15)