Four techniques for assessing differences between least-squares estimators of regression coefficients from group and individual-level data are summarized. The utility and suitability of all four approaches are discussed when (1) data are grouped by a nominal characteristic; (2) there are multiple regressors; or (3) individual-level data cannot be…

Two questions are investigated here: What should the unit of analysis be in investigations of educational effects and on what basis should the units be chosen Under what conditions can relationships among measurements on individuals be estimated from the relationships among measurements on aggregates of individuals? Models using standard analysis…