Measuring Partisan Bias in Single-Member District Electoral Systems
Public Policy Institute of California
May 29, 2013
In recent decades, the literature has coalesced around either symmetry or responsiveness as measures of partisan bias in single-member district systems. I argue neither accurately captures the traditional idea of an "efficient" gerrymander, where one party claims more seats without more votes. I suggest a better measure of efficiency and then use this new measure to reconsider a classic study of partisan gerrymandering. Contrary to the original study findings, I show that the effects of party control on bias are small and decay rapidly, suggesting that redistricting is at best a blunt tool for promoting partisan interests.
Number of Pages in PDF File: 46
Keywords: redistricting, gerrymandering, partisan bias, electoral systems, elections, American politics
Date posted: January 2, 2013 ; Last revised: July 8, 2013