Bell Curve

Appendix 6Regression Analyses fromChapter 14This appendix presents the regression analyses underlying the presentationin Chapter 14.The results in Chapter 14 and in this appendix are based on separateregressions for each of the three ethnic groups in question (black,Latino, and white). This procedure was chosen in preference to a singleregression entering ethnicity as a nominal variable so that the relationshipswould not be constrained to a single slope. The regressionsused the entire NLSY sample, with exclusions as noted for specificanalyses, applying 1990 sample weights.LOGISTIC REGRESSIONSAll the indicators in Chapter 14 except for those involving income arebinary variables, and the mode of analysis is logistic regression. The interpretationof logistic regressions is discussed in Appendix 4.The data tables use short labels for the indicators. The full descriptionof each indicator and associated characteristics of the analysis areshown in Table 1.Table 2 first summarizes the results, by ethnic group, for four sets ofregressions: when age (zAge) is the only independent variable, whenage and IQ (zAFQT) are independent variables, when age and parentalSES (zSES) are independent variables, and when all three are enteredas independent variables. Three basic questions are then examined:1. How much do ethnic differences change when IQ is taken intoaccount?2. How much do ethnic differences change when parental SES istaken into account?3. What are the comparative roles of 1Q and parental SES?