Irrational Ratios and the Problems of Ecological Units

• In Event: 4351 - Measurement Issues in Social Statistical Models

Abstract

It is common for social scientists to use formal quantitative methods to compare ecological units such as towns, schools, or nations. In many cases, the size of these units in terms of the number of individuals subsumed in each differs substantially. When the variables in questions are counts, there is generally some attempt to neutralize differences in size by turning variables into ratios or by controlling for size. We demonstrate that in most cases, these methods are quite unjustified, and may well introduce spurious relations between variables. We suggest local regressions as a simple diagnostic and Generalized Additive Models as a superior modeling strategy, with double-residualized regressions as a backup for certain cases.

Authors

• Benjamin Rohr, University of Chicago

• John Levi Martin