High School Graduation Rates in Maryland Technical Appendix Data All data for the brief were obtained from the National Center for Education Statistics Common Core of Data (CCD). This data represents the 2008-09 school year, which is the most recent year for which graduation rates were available. The CCD provides data that allows for the calculation of district-level averaged freshman graduation rates. Specifically, it provides the number of diplomas that were awarded in the district in a given year, as well as the average number of 8 th, 9 th, and 10 th grade students four years earlier (averaged freshman cohort). The ratio of these two numbers gives the averaged freshman graduation rate. State graduation rates were calculated by adding up the total number of diplomas awarded in each state and dividing by the total averaged freshman cohort size in each state. All public school districts that reported data were used in this analysis. No data were available for any districts in California or Nevada so these states were omitted. Method Predicted graduation rates were constructed using regression analysis. This method is used to estimate the relationship between a set of predictor variables, or covariates, and an outcome variable (in this case, graduation rate). When we do this analysis using every district in the country, we learn how on average changes in a predictor variable might change a district s graduation rate. Once this relationship is estimated, we use actual values of the predictor variables from Maryland school districts to predict graduation rates. For example, if we estimate that each percentage point of a district s percentage of white students is associated with graduation rates that are 0.4 percentage points higher, then if a district were 50 percent white, this would contribute 20 (50 x 0.4) percentage points to that district s predicted graduation rate. The sum of all of these pieces across all predictor variables (some may be negative) gives the predicted graduation rate for a given district. Regressions were run on all public school districts in the country with non-missing data and that had students enrolled in 12 th grade in the 2008-09 school year (i.e., they had students in a position to graduate). The final sample included 9,947 districts. Even with the omission of California and Nevada, this accounts for over 77% of all twelfth grade students in the country (and, in fact, over 77% of all ninth through twelfth grade students). Table 1 presents descriptive statistics for the data in the full sample, as well as for the districts in Maryland. The variables in this table fall into several distinct categories: Race and gender composition of high-school grade students. A long line of research has demonstrated the association between academic performance and race and gender. To capture this relationship we include measures of the percentage of the population of students in a district by race and gender at each high school grade. District-wide student characteristics. These variables capture the characteristics of the entire student body in a district. District-wide measures include the percentage of students in the district by race/ethnicity, and the percentage of students who receive free 1
or reduced-price lunch, as well as the overall total number of students, and the number of students in high school (grades 9 through 12). Note that there is some conceptual overlap between these district-wide variables and the variables that describe just high school age students. However, the results of the graduation rate predictions are remarkably similar whether overall district characteristics, district characteristics of high school students, or both sets of variables are included in the model. For the sake of precision, we use both sets of variables. District-wide school characteristics. These variables account for the different types of schools and include the total number of schools in the district, the percentage of schools that qualify as state or federal Title I schools, and the student-teacher ratio in the district, and the amount of total revenue districts receive per student. Other district characteristics. Finally, we account for the total amount of revenue districts have per student, and the location of a district (city, suburb, town). The regression used to estimate the predicted graduation rate regressed the averaged freshman graduation rate on each of the variables listed in Table 1 as well as state fixed effects. These fixed effects work to control for state-level differences in district graduation performance. Table 2 gives the coefficients for the results of this regression. 2
Table 1. Descriptive Statistics of the Sample All districts in sample (N=9,947) All districts in Maryland (N=24) Variable Mean Std. Dev. Min Max Mean Std. Dev. Min Max Averaged freshman graduation rate 81.776 13.329 0.500 100.000 82.488 8.741 56.400 93.500 District percent Native American, grade 9, males 0.016 0.061 0.000 0.800 0.002 0.002 0.000 0.008 District percent Native American, grade 9, females 0.015 0.058 0.000 1.000 0.002 0.002 0.000 0.007 District percent Asian, grade 9, males 0.007 0.018 0.000 0.500 0.015 0.021 0.000 0.081 District percent Asian, grade 9, females 0.007 0.016 0.000 0.350 0.014 0.017 0.000 0.068 District percent Hispanic, grade 9, males 0.048 0.091 0.000 0.750 0.026 0.026 0.003 0.117 District percent Hispanic, grade 9, females 0.044 0.084 0.000 0.673 0.022 0.023 0.003 0.110 District percent Black, grade 9, males 0.049 0.099 0.000 1.000 0.150 0.120 0.003 0.489 District percent Black, grade 9, females 0.045 0.092 0.000 0.714 0.136 0.106 0.000 0.429 District percent White, grade 9, males 0.396 0.150 0.000 1.000 0.333 0.131 0.023 0.509 District percent White, grade 9, females 0.369 0.144 0.000 1.000 0.300 0.118 0.020 0.482 District percent Pacific Islander, grade 9, males 0.000 0.001 0.000 0.046 0.000 0.000 0.000 0.000 District percent Pacific Islander, grade 9, females 0.000 0.001 0.000 0.067 0.000 0.000 0.000 0.000 District percent multiracial, grade 9, males 0.000 0.002 0.000 0.060 0.000 0.000 0.000 0.000 District percent multiracial, grade 9, females 0.000 0.003 0.000 0.125 0.000 0.000 0.000 0.000 District percent Native American, grade 10, males 0.015 0.060 0.000 0.800 0.002 0.002 0.000 0.005 District percent Native American, grade 10, females 0.015 0.056 0.000 0.667 0.002 0.002 0.000 0.006 District percent Asian, grade 10, males 0.007 0.018 0.000 0.438 0.016 0.020 0.000 0.078 District percent Asian, grade 10, females 0.007 0.018 0.000 0.582 0.014 0.018 0.000 0.072 District percent Hispanic, grade 10, males 0.046 0.088 0.000 0.800 0.023 0.023 0.000 0.110 District percent Hispanic, grade 10, females 0.043 0.084 0.000 1.000 0.021 0.021 0.000 0.097 District percent Black, grade 10, males 0.047 0.094 0.000 1.000 0.135 0.111 0.000 0.437 District percent Black, grade 10, females 0.046 0.098 0.000 1.000 0.135 0.115 0.000 0.479 3
District percent White, grade 10, males 0.395 0.149 0.000 1.000 0.333 0.126 0.025 0.515 District percent White, grade 10, females 0.374 0.143 0.000 1.000 0.319 0.121 0.021 0.482 District percent Pacific Islander, grade 10, males 0.000 0.001 0.000 0.063 0.000 0.000 0.000 0.000 District percent Pacific Islander, grade 10, females 0.000 0.001 0.000 0.054 0.000 0.000 0.000 0.000 District percent multiracial, grade 10, males 0.000 0.003 0.000 0.089 0.000 0.000 0.000 0.000 District percent multiracial, grade 10, females 0.000 0.003 0.000 0.063 0.000 0.000 0.000 0.000 District percent Native American, grade 11, males 0.015 0.059 0.000 0.857 0.001 0.001 0.000 0.003 District percent Native American, grade 11, females 0.014 0.058 0.000 1.000 0.001 0.002 0.000 0.006 District percent Asian, grade 11, males 0.008 0.018 0.000 0.488 0.016 0.021 0.000 0.084 District percent Asian, grade 11, females 0.008 0.018 0.000 0.451 0.015 0.018 0.000 0.076 District percent Hispanic, grade 11, males 0.043 0.084 0.000 0.750 0.020 0.020 0.003 0.097 District percent Hispanic, grade 11, females 0.041 0.083 0.000 1.000 0.018 0.019 0.001 0.090 District percent Black, grade 11, males 0.045 0.091 0.000 1.000 0.125 0.104 0.003 0.404 District percent Black, grade 11, females 0.046 0.099 0.000 0.750 0.137 0.125 0.000 0.507 District percent White, grade 11, males 0.397 0.147 0.000 1.000 0.343 0.125 0.025 0.517 District percent White, grade 11, females 0.380 0.142 0.000 1.000 0.322 0.124 0.026 0.470 District percent Pacific Islander, grade 11, males 0.000 0.001 0.000 0.088 0.000 0.000 0.000 0.000 District percent Pacific Islander, grade 11, females 0.000 0.001 0.000 0.071 0.000 0.000 0.000 0.000 District percent multiracial, grade 11, males 0.000 0.003 0.000 0.115 0.000 0.000 0.000 0.000 District percent multiracial, grade 11, females 0.000 0.002 0.000 0.072 0.000 0.000 0.000 0.000 District percent Native American, grade 12, males 0.014 0.059 0.000 1.000 0.001 0.001 0.000 0.005 District percent Native American, grade 12, females 0.014 0.058 0.000 1.000 0.002 0.002 0.000 0.006 District percent Asian, grade 12, males 0.008 0.018 0.000 0.409 0.015 0.020 0.000 0.080 District percent Asian, grade 12, females 0.007 0.017 0.000 0.359 0.015 0.018 0.000 0.073 District percent Hispanic, grade 12, males 0.040 0.082 0.000 0.700 0.017 0.020 0.000 0.095 District percent Hispanic, grade 12, females 0.040 0.084 0.000 0.833 0.017 0.019 0.000 0.091 4
District percent Black, grade 12, males 0.043 0.090 0.000 1.000 0.119 0.101 0.008 0.390 District percent Black, grade 12, females 0.046 0.100 0.000 0.773 0.131 0.125 0.000 0.520 District percent White, grade 12, males 0.397 0.145 0.000 1.000 0.337 0.122 0.029 0.483 District percent White, grade 12, females 0.385 0.142 0.000 1.000 0.345 0.124 0.029 0.530 District percent Pacific Islander, grade 12, males 0.000 0.001 0.000 0.069 0.000 0.000 0.000 0.000 District percent Pacific Islander, grade 12, females 0.000 0.002 0.000 0.111 0.000 0.000 0.000 0.000 District percent multiracial, grade 12, males 0.000 0.002 0.000 0.100 0.000 0.000 0.000 0.000 District percent multiracial, grade 12, females 0.000 0.003 0.000 0.216 0.000 0.000 0.000 0.000 District percent Native American 0.029 0.110 0.000 1.000 0.004 0.002 0.001 0.008 District percent Asian 0.015 0.031 0.000 0.729 0.033 0.040 0.003 0.156 District Percent Hispanic 0.096 0.170 0.000 0.999 0.055 0.049 0.003 0.221 District percent Black, 0.089 0.180 0.000 1.000 0.268 0.213 0.005 0.884 District percent White, 0.762 0.259 0.000 1.000 0.640 0.240 0.047 0.988 District percent Pacific Islander 0.000 0.002 0.000 0.099 0.000 0.000 0.000 0.000 District percent multiracial 0.001 0.005 0.000 0.143 0.000 0.000 0.000 0.000 District percent free and reduced-price lunch 0.423 0.208 0.000 0.996 0.347 0.157 0.126 0.731 Number of schools in district 7.854 17.771 1.000 643.000 61.250 68.514 8.000 215.000 Total district enrollment 3838.455 11289.120 22.000 421430.000 35157.540 40565.900 2219.000 139282.000 District enrollment, grades 9-12 1156.466 3277.960 8.000 117302.000 11141.170 12858.200 685.000 44867.000 Percent federal Title I Schools 0.742 0.260 0.042 1.000 0.275 0.151 0.049 0.580 Percent state Title I Schools 0.497 0.460 0.000 1.000 0.791 0.355 0.000 1.000 District expenditure per student ($) 12579.760 4974.748 4964.948 108540.000 15412.090 1823.751 13040.990 21412.380 District student-teacher ratio 14.602 8.474 1.900 602.200 14.080 1.146 11.477 16.463 District in city 0.062 0.242 0.000 1.000 0.083 0.282 0.000 1.000 District in suburb 0.180 0.385 0.000 1.000 0.417 0.504 0.000 1.000 District in town 0.204 0.403 0.000 1.000 0.125 0.338 0.000 1.000 5
Table 2. Estimated Regression Coefficients Variable Estimated Coefficient District percent Native American, grade 9, males 7.622 District percent Native American, grade 9, females 10.634 District percent Asian, grade 9, males 9.668 District percent Asian, grade 9, females 1.170 District percent Hispanic, grade 9, males 10.584 District percent Hispanic, grade 9, females 15.941 District percent Black, grade 9, males -16.636 District percent Black, grade 9, females 1.964 District percent White, grade 9, males 9.744 District percent White, grade 9, females 13.392 District percent Pacific Islander, grade 9, males 146.988 District percent Pacific Islander, grade 9, females 264.162 District percent multiracial, grade 9, males 76.097 District percent multiracial, grade 9, females -78.204 District percent Native American, grade 10, males -46.952 * District percent Native American, grade 10, females -39.636 * District percent Asian, grade 10, males -35.724 * District percent Asian, grade 10, females -50.959 * District percent Hispanic, grade 10, males -61.783 * District percent Hispanic, grade 10, females -62.450 * District percent Black, grade 10, males -61.262 * District percent Black, grade 10, females -56.214 * District percent White, grade 10, males -50.827 * District percent White, grade 10, females -52.644 * District percent Pacific Islander, grade 10, males 270.184 District percent Pacific Islander, grade 10, females -103.127 District percent multiracial, grade 10, males 121.869 District percent multiracial, grade 10, females 18.269 District percent Native American, grade 11, males 2.012 District percent Native American, grade 11, females 7.877 District percent Asian, grade 11, males -1.908 District percent Asian, grade 11, females 14.200 District percent Hispanic, grade 11, males 14.301 District percent Hispanic, grade 11, females 12.086 District percent Black, grade 11, males 9.053 District percent Black, grade 11, females 16.582 District percent White, grade 11, males 8.182 District percent White, grade 11, females 7.424 6
District percent Pacific Islander, grade 11, males -305.621 * District percent Pacific Islander, grade 11, females 203.822 District percent multiracial, grade 11, males 7.382 District percent multiracial, grade 11, females -237.908 * District percent Native American, grade 12, males 34.868 * District percent Native American, grade 12, females 37.841 * District percent Asian, grade 12, males 55.624 * District percent Asian, grade 12, females 24.386 District percent Hispanic, grade 12, males 30.414 * District percent Hispanic, grade 12, females 35.653 * District percent Black, grade 12, males 33.453 * District percent Black, grade 12, females 19.435 District percent White, grade 12, males 29.446 * District percent White, grade 12, females 25.279 * District percent Pacific Islander, grade 12, males -61.141 District percent Pacific Islander, grade 12, females -27.826 District percent multiracial, grade 12, males 51.834 District percent multiracial, grade 12, females -46.298 District percent Native American 2.897 District percent Asian 33.889 * District Percent Hispanic 18.502 District percent Black, 38.518 * District percent White 27.183 * District percent Pacific Islander 29.326 District percent multiracial 1.158 District percent free and reduced-price lunch -15.686 * Number of schools in district -0.114 * Total district enrollment -0.001 * District enrollment, grades 9-12 0.004 * Percent federal Title I Schools -1.704 * Percent state Title I Schools -2.696 * District expenditure per student ($) 0.000 * District student-teacher ratio 0.013 District in city -3.968 * District in suburb -0.873 * District in town -0.927 * Intercept 70.425 * 7