Jeff Jacoby

If you've heard it once, you've heard it a thousand times: It's your civic duty to vote. Between now and Election Day -- unless you're planning an extended session in a sensory-deprivation tank -- you'll no doubt hear it again. And again.

Don't believe it. It's not your duty to vote.

Not that I'm against voting. I was 9 when I first saw the inside of a voting booth. It was Election Day, 1968. My father took me with him early in the morning when he went to vote and let me pull the lever for his candidate -- Hubert H. Humphrey. (My mother cast her ballot later that day for Richard M. Nixon.) Once I turned old enough to vote I became an Election Day regular. My candidates don't usually win, and even those who do routinely disappoint me in office. Still, "don't vote -- it only encourages them" has never been my philosophy.

As a father I've taken my own children with me to the polls. In 2004 my then-7-year-old wondered why so many people were standing in line to vote, when there was no law requiring them to do so and no doubt about which presidential candidate would carry our state. Part of the reason, I told him, is that many people like to vote. We relish the egalitarian ritual of Election Day -- citizens of every rank coming together as equals to peacefully choose their leaders. Even when the outcome is a foregone conclusion, voting is an act of democratic self-government that many Americans enjoy being part of.

But plenty of other Americans don't feel that way. Tens of millions of eligible voters routinely sit out national elections, and there is no legitimate basis for scorning them. Quite the contrary. Though it may be unfashionable to say it, there are perfectly sound reasons not to vote. For one thing, your vote almost certainly won't matter.

The odds that any single voter will actually determine how an election turns out are "very, very, very slim," wrote Freakonomics authors Stephen J. Dubner and Steven D. Levitt in 2005, citing research that analyzed more than 56,000 congressional and state legislative elections sating back to 1898. Just eight of those elections were decided by a single vote -- and only one of those eight was a contest for a US House seat. In a presidential election, the average voter's impact is even less significant. Even in so-called battleground states, the likelihood that any given voter's participation will affect the outcome is infinitesimal -- and most of us don't live in battleground states. Americans who decide they have more important things to do with their time than cast a vote that won't make a difference anyway are probably right.

That's even truer for eligible voters who don't feel they know enough -- or who don't care enough -- to cast an informed vote. That's not meant as a put-down. As Harvard economist Greg Mankiw points out, even reliable voters who never miss an election will often skip down-ballot races about which they have little or no information.

"In practice, this means that you are relying on your fellow citizens to make the right choice," writes Mankiw, a former chairman of the Council of Economic Advisers. "But this can be perfectly rational. If you really don't know enough to cast an intelligent vote, you should be eager to let your more informed neighbors make the decision."

If that's the case when it comes to elections for registrar of deeds or county commissioner, why not in contests for state representative, US senator, or president? Like buying stocks or undergoing surgery, the election of government officials can have serious consequences. We don't hector Americans to make uninformed decisions about investments or medical treatment. What societal advantage is there in badgering people with no interest in candidates or elections to go to the polls anyway?

"But it's your civic duty to vote!"

No, it isn't. You have the right to vote, not a duty to do so. In much the same way, you have the right to worship freely, the right to express your views, the right to run for public office -- but no obligation to do any of them. Just as freedom of religion encompasses the freedom to practice no religion, your freedom to vote for the candidate of your choice includes the freedom to vote for no candidate at all.

"I leave you with the words of my mom," said CBS newsman Bob Schieffer, wrapping up the final presidential debate in Boca Raton last week. "Go vote. It makes you feel big and strong." Great advice -- for those who feel that way. But there's nothing wrong with staying home for those who don't.

(Jeff Jacoby is a columnist for The Boston Globe).