Exit, Voice and Political Change: Evidence from Swedish Mass Migration to the United States. A Comment on Karadja and Prawitz (Journal of Political Economy, 2019)

Abstract

In this comment, I revisit the question raised in Karadja and Prawitz (2019) concerning a causal relationship between mass emigration and long-run political outcomes. I discuss a number of potential problems with their instrumental variable analysis. First, there are at least three reasons why their instrument violates the exclusion restriction: (i) failing to control for internal migration, (ii) insufficient control for confounders correlated with their instrument, and (iii) emigration measured with a nonclassical measurement error. Second, I also discuss two problems with the statistical inference, both of which indicate that the instrument does not fulfill the relevance condition, i.e., the instrument is not sufficiently correlated with the endogenous variable emigration. Correcting for any of these problems reveals that there is no relationship between emigration and political outcomes.