Gerrymandering in comparative perspective

Abstract

Using data from the Electoral Integrity Project, we measure the level of gerrymandering according to country expert surveys in Lower House elections in 54 democracies from the second half of 2012 until the first half of 2015. We show that majoritarian systems are more prone to gerrymandering than mixed-member and above all in Proportional Representation (PR) systems. When majoritarian systems are employed in large countries, gerrymandering is exacerbated. Per capita GDP and the age of electoral systems do not significantly affect gerrymandering.