The Effects of Automated Redistricting and Partisan Strategic Interaction on Representation: The Case of Mexico
Altman M, Magar E, McDonald MP, Trelles A. The Effects of Automated Redistricting and Partisan Strategic Interaction on Representation: The Case of Mexico. Social Science Research Network [Internet]. Working Paper.
In the U.S. redistricting is deeply politicized and often synonymous with gerrymandering -- the manipulation of boundaries to promote the goals of parties, incumbents, and racial groups. In contrast, Mexico’s federal redistricting has been implemented nationwide since 1996 through automated algorithms devised by the electoral management body (EMB) in consultation with political parties. In this setting, parties interact strategically and generate counterproposals to the algorithmically generated plans in a closed-door process that is not revealed outside the bureaucracy. Applying geospatial statistics and large-scale optimization to a novel dataset that has never been available outside of the EMB, we analyze the effects of automated redistricting and partisan strategic interaction on representation. Our dataset comprises the entire set of plans generated by the automated algorithm, as well as all the counterproposals made by each political party during the 2013 redistricting process. Additionally, we inspect the 2006 map with new data and two proposals to replace it towards 2015 in search for partisan effects and political distortions. Our analysis offers a unique insight into the internal workings of a purportedly autonomous EMB and the partisan effects of automated redistricting on representation.