For years, researchers warned that laws requiring voters to show certain forms of photo identification at the poll would discriminate against racial minorities and other groups. Now, the first study has been released showing that the proliferation of voter ID laws in recent years has indeed driven down minority voter turnout, and by a significant amount.
In a new paper entitled “Voter Identification Laws and the Suppression of Minority Votes”, researchers at the University of California, San Diego — Zoltan Hajnal, Nazita Lajevardi — and Bucknell University — Lindsay Nielson — used data from the annual Cooperative Congressional Election Study to compare states with strict voter ID laws to those that allow voters without photo ID to cast a ballot. They found a clear and significant dampening effect on minority turnout in strict voter ID states.
(Note: ThinkProgress was provided an updated version of the paper [not currently available on the web] that includes data from the 2014 elections. The numbers in this article reflect the updated paper, not the web version linked above.)
Looks like this paper is in draft—not sure if it is under peer review submission (yet).