This paper analyzes the determinants of the geographic dispersion of unemployment rates. The model presented here recognizes that structural labor market relationships differ across areas and that area unemployment rates and some of the explanatory variables are determined simultaneously. Most importantly, the methodology introduced here provides an estimate of the impact of each of the explanatory variables on the overall dispersion of unemployment rates, allowing comparison of several competing hypotheses that purport to explain why areas differ so widely in terms of their unemployment rates. The empirical results indicate that inter‐area differences in product market demand and in sensitivity to changes in conditions in the product market are the most important factors accounting for geographic differences in unemployment rates. More generally, the results indicate that unemployment rates differ widely across areas not so much because areas differ in terms of the underlying characteristics that determine unemployment rates but because areas are so heterogeneous with respect to labor market structur