TY  - JOUR
AU  - Gelman,Andrew
AU  - Silver,Nate
AU  - Edlin,Aaron
TI  - What is the probability your vote will make a difference?
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 15220
PY  - 2009
Y2  - August 2009
UR  - http://www.nber.org/papers/w15220
L1  - http://www.nber.org/papers/w15220.pdf
N1  - Author contact info:
Andrew Gelman
Department of Statistics
and Department of Political Science
Columbia University
New York, NY 10027
E-Mail: gelman@stat.columbia.edu

Nate Silver
Baseball Prospectus
Chicago IL
E-Mail: 538dotcom@gmail.com

Aaron Edlin
The Richard W. Jennings '39 Endowed Chair
University of California, Berkeley
Department of Economics and School of Law
Berkeley, CA   94720-7200
Tel: 510/642-4719
Fax: 510/642-3767
E-Mail: edlin@econ.berkeley.edu
AB  - One of the motivations for voting is that one vote can make a difference.  In a presidential election, the probability that your vote is decisive is equal to the probability that your state is necessary for an electoral college win, times the probability the vote in your state is tied in that event.  We computed these probabilities a week before the 2008 presidential election, using state-by-state election forecasts based on the latest polls.  The states where a single vote was most likely to matter are New Mexico, Virginia, New Hampshire, and Colorado, where your vote had an approximate 1 in 10 million chance of determining the national election outcome.  On average, a voter in America had a 1 in 60 million chance of being decisive in the presidential election.
ER  -