Detecting Neglected Parameter Heterogeneity with Chow Tests

The paper demonstrates through a number of Monte-Carlo experiments that, for the type of cross-section data sets typically encountered in applied economics, Chow tests on sorted variations of the data matrix can detect neglected parameter heterogeneity. The paper focuses on heterogeneity in the behavioral responses of economic actors that belong to different economically meaningful groups, such as the young, middle-aged, and old. Since the suggested methodology is easy to implement yet powerful, its routine use by applied economists would be desirable given the very significant estimation bias that can result from neglecting parameter heterogeneity.