This working paper from Marc Meredith and Neil Malhotra was just posted on the political methodology working paper archive. It’s an interesting effort to study the effects of vote-by-mail on election outcomes. I’ve only skimmed it, and also suspect that Paul and Thad might have some thoughts about this research project:

Title: Can October Surprise? A Natural Experiment Assessing
Late Campaign Effects

Authors: Marc Meredith, Neil Malhotra

Entrydate: 2008-10-14 17:01:06

Keywords: Vote by mail, natural experiment, campaign effects,
momentum, convenience voting, regression discontinuity

Abstract: One consequence of the proliferation of vote-by-mail
(VBM) in certain areas of the United States is the opportunity
for voters to cast ballots weeks before Election Day.
Understanding the ensuing effects of VBM on late campaign
information loss has important implications for both the study
of campaign dynamics and public policy debates on the expansion
of convenience voting. Unfortunately, the self-selection of
voters into VBM makes it difficult to casually identify the
effect of VBM on election outcomes. We overcome this
identification problem by exploiting a natural experiment, in
which some precincts are assigned to be VBM-only based on an
arbitrary threshold of the number of registered voters. We
assess the effects of VBM on candidate performance in the 2008
California presidential primary via a regression discontinuity
design. We show that VBM both increases the probability of
selecting candidates who withdrew from the race in the interval
after the distribution of ballots but before Election Day and
affects the relative performance of candidates remaining in the
race. Thus, we find evidence of late campaign information loss,
pointing to the influence of campaign events and momentum in
American politics, as well as the unintended consequences of
convenience voting.

http://polmeth.wustl.edu/retrieve.php?id=839