The Role of Partisan Gerrymandering in U.S. Elections

18 Pages Posted: 18 Mar 2019

See all articles by Eric McGhee

Eric McGhee

Public Policy Institute of California

Date Written: August 25, 2017


The literature on partisan bias in U.S. redistricting has emphasized the role of incidental or accidental causes like incumbency and political geography, while questioning the importance of deliberate gerrymandering. I reconsider this settled understanding with a wider range of data, a robust difference-in-differences design, and a new measure of bias called the “efficiency gap” that measures the differential wasted votes of a gerrymander directly. I show that the accepted notion of a null effect for gerrymandering was appropriate for an earlier time period, but that gerrymandering has played a much larger and more durable role in the last two rounds of redistricting. I conclude that it is no longer certain that gerrymandering will play a modest role in the future.

Keywords: redistricting, gerrymandering, political representation, elections, election reform

Suggested Citation

McGhee, Eric, The Role of Partisan Gerrymandering in U.S. Elections (August 25, 2017). Available at SSRN: or

Eric McGhee (Contact Author)

Public Policy Institute of California ( email )

500 Washington Street
Suite 800
San Francisco, CA 94111
United States
415-291-4439 (Phone)

Here is the Coronavirus
related research on SSRN

Paper statistics

Abstract Views
PlumX Metrics