Yang and Land (2006) and Yang (forthcoming-b) developed a mixed (fixed and random) effects model for the age–period–cohort (APC) analysis of micro data sets in the form of a series ofrepeated cross-section sample surveys that are increasingly available to demographers. The authors compare the fixedversus random-effects model specifications for APC analysis. They usedata on verbal test scores from 15 cross sections of the General Social Survey (GSS), 1974 to 2000, for substantive illustrations. Strengths and weaknesses are identified for both the random-and fixed-effects formulations. However, under each of the two data conditions studied, the random-effects hierarchical APC model is the most appropriate specification. While additionalanalyses and comparisons of random- and fixed-effects APC models using other data sets are necessary before generalizations can be drawn, this finding is consistent with results from othermethodological studies with unbalanced data designs.
Key Words: age-period-cohort analysis • fixed effects • random effects • General Social Survey