Wednesday, October 27, 2010

Assessing the Power of One at the Polls

Copyright, The New York Times Company

Signs outside an early voting station in Lauderhill, Fla.Joe Raedle/Getty Images Signs outside an early voting station in Lauderhill, Fla.

Candidates for office can be heard these days telling constituents, “I need your vote.” But, actually, they do not: the outcomes of civic elections almost never come down to a single vote.

A pivotal vote is one cast in an election that was tied or decided by only one vote. The vote is pivotal because the election outcome might be different if that vote were cast differently. If a person votes next week with the purpose of helping her or his perceived right candidates win, that person is either delusional or extraordinarily concerned with rare events, because essentially all votes cast in civic elections are not pivotal: practically all civic elections conclude with a winner’s vote margin that is two or greater.

We have been electing presidents for more than 200 years, and none of those elections came down to one vote. Even the 2000 election between Al Gore and George W. Bush had a margin greater than two votes in Florida (and much wider margins in every other state), so any single voter in Florida that year could have voted differently, and George W. Bush would still have been elected.

An election of a United States senator, or a governor, has never in the history of the United States been decided by one vote. University of Chicago PhD Charles Hunter and I studied almost 100 years of elections of members of Congress – almost 20,000 of them in which an aggregate two billion votes were cast – and only one election was determined by a single vote of the 40,000 cast (that was in the New York’s 36th Congressional District in 1910). And that election had a recount that determined the election was decided by a margin of six votes, rather than one.

Thus, when it comes to elections to federal office, history suggests that the chances that your vote next week will change the winner of the election is less than one in 100,000; more people die in an election year in car crashes than cast a pivotal vote in a federal election.

Dr. Hunter and I also studied 21 years of elections to state legislatures in the 50 states. Our data included more than 50,000 elections with an aggregate of about a billion votes cast. Those elections were markedly smaller than the federal elections and therefore more likely to come down to one vote.

Still, only nine of these came down to one vote (before recounts), and included a grand total of less than 40,000 pivotal votes. So the probability of a pivotal vote in these elections was less than one in 25,000. (The odds are somewhat higher – one in 15,000 for the state elections and one in 89,000 for Congressional elections – if the election actually has more than one candidate; a number of elections do not, such as this year’s election in Florida’s 21st Congressional District).

Many times we cannot know for sure whether next week’s will be the election when your district’s Congressional balloting ends in a tie. Tomorrow could be the day when the lottery draws your lucky number, but few of us make the effort and accept the expense to be sure that no lottery is ever drawn without our owning a ticket. In each case, the outcome of interest is much too rare to justify action by itself.

If the election were not tied, your vote might help your, say, candidate win by 18,001 votes rather than just 18,000. Representatives who win with bigger margins can act differently in office than they otherwise might. But your representative will not change his habits or commitments based on 18,001 rather than 18,000 votes. However you look at it, the expected effect of your vote is minuscule.

Many eligible voters will not exercise their right to vote next week, and some think their vote does not matter. Civic pride, or just having fun, may be good reasons for you to vote, but history suggests that next week’s winners will not actually need your vote.

1 comment:

Trevor Tombe said...

Interesting post. In Canada - where I'm from - things may be different. At our Federal Government level, political parties that achieve more than 5% of the popular vote receive public funding each year proportional to votes received. I think it is a little under $2 per year. So, individual voters can always point to the five-ten bucks they "gave" to this party or that party due directly to their vote.