Two Sides of the Same Coin? Employing Granger Causality Tests in a Time Series Cross-Section Framework

In this paper, we introduce a recently developed methodology for assessing the assumption of causal homogeneity in a time series cross-section Granger framework. Following a description of the procedure and the analytical contexts for which it is appropriate, we implement this new approach to examine the transformation of the post-World War II party system in the South. Specifically, we analyze the causal relationship between black mobilization and GOP growth in the region. We find that black mobilization Granger caused Republican growth throughout the South, whereas Republican growth Granger caused black mobilization only in the deep South. We discuss the substantive significance of our results and conclude with guidelines for the appropriate use of this procedure and suggestions for future extensions of the method.