Don’t blame gerrymandering: the update

by Andrew Gelman on February 18, 2009 · 1 comment

in Campaigns and elections

This 2006 article by Alan Abramowitz, Brad Alexander, and Matthew Gunning finds, consistent with our earlier research, that declining competitiveness in U.S. House elections cannot be explained by gerrymandering:

Competition in U.S. House elections has been declining for more than 50 years and, based on both incumbent reelection rates and the percentage of close races, the 2002 and 2004 House elections were the least competitive of the postwar era. This article tests three hypotheses that attempt to explain declining competition in House elections: the redistricting hypothesis, the partisan polarization hypothesis, and the incumbency hypothesis.We find strong support for both the partisan polarization hypothesis and the incumbency hypothesis but no support for the redistricting hypothesis. Since the 1970s there has been a substantial increase in the number of House districts that are safe for one party and a substantial decrease in the number of marginal districts. However, this shift has not been caused by redistricting but by demographic change and ideological realignment within the electorate. Moreover, even in the remaining marginal districts most challengers lack the financial resources needed to wage competitive campaigns. The increasing correlation among district partisanship, incumbency, and campaign spending means that the effects of these three variables tend to reinforce each other to a greater extent than in the past. The result is a pattern of reinforcing advantages that leads to extraordinarily uncompetitive elections.

So that’s the story. Don’t blame gerrymandering.

P.S. They didn’t cite our 1991 AJPS article! A regrettable oversight, I’m sure. . . .

{ 1 comment }

Eric McGhee February 18, 2009 at 8:04 pm

Yes, I’ve seen this piece. However, I would still argue that your earlier research should be updated, since a big part of it concerned legislative elections, and Abramowitz, et al don’t look at legislatures. One might argue that state legislators are uniquely tempted to draw safe districts for themselves (and probably have more districts available in any given state to monkey around with). My suspicion is your earlier conclusions will hold, but it would be a valuable contribution nonetheless.

Comments on this entry are closed.

Previous post:

Next post: