Today, people in the Atlanta metropolitan area will head to the polls to decide on a sales tax increase to fund infrastructure projects in and around the city. Atlanta, the seat of Fulton County, will see its sales tax increase from 8% to 9%. Most of the electorate is polarized and despite the intensive get-out-the-vote operations by both sides, none of it will matter. At least, not on the individual level. The problem is that voting is for chumps because one vote doesn't matter.
Now, before you play the "well what if everybody thought that way?" card, let me just cut you off right there. If everybody did indeed think that way, then the calculus changes and then voting would be extremely valuable. But it's useless to say that because most people don't think that way. If your grandfather had a vagina he'd be your grandmother. It's useless to speculate on a reality that doesn't exist.
An individual vote, in and of itself, only matters if it casts the deciding ballot. That is, voting or not voting a certain way could change the outcome of the election. If the election is decided by a single vote, then the people on the winning side can all pat themselves on the back and say that their votes mattered. If any of them hadn't had voted, then the outcome would have been different. If the margin of victory is greater than a single vote, then the ability to assign importance to each individual vote essentially becomes impossible.
In any significant election, where turnout is expected to be at least six figures, the possibility of this happening is impossibly small. For example, let's say we know beforehand that the election will have a turnout of exactly 100,001 voters voting for A or B. The polls show an absolute nailbiter, with a 51/49 split in favor of A. If we assume that the polling represents the likelihood of any random person's vote, then in order to have our 50%+1 scenario (where all the votes on the winning side matter), we'd need either A or B to have 50,001 votes.
Mathematically, this will never happen. If 51% of voters will vote for A, that puts A at approximately 51,001 votes. In order for every vote to count, then in the actual instance of voting, 1000 votes from A have to take the less likely route and go for B instead. It's like flipping a slightly biased coin that lands on heads 51 out of 100 times. So the probability of that coin landing on tails 1000 times in a row is approximately .51^1000. You have a better chance of winning the Powerball lottery twenty times in a row. Let's say the election is even closer than that and the probability is 50.1% to 49.9%. That brings down the expected value to 50,101 votes for A. You still need 100 votes to go the other way. You have a better chance of winning the Powerball lottery twice in a row.
Even on the off chance that such an event miraculously occurs, your vote probably won't matter anyways. Because in such a close election, the actual outcome will be decided by the court system. If it's a state election, the state Supreme Court has the final say. If it's a Federal election, the Supreme Court has the final say. This brings me to Bush v Gore.
In the end, the recount (and the result of the election) depended on a bunch of old, possibly senile volunteers recounting the ballots by hand. They had a billion times more influence on the election than your vote did, and even then it was still worthless. If some enterprising Democrat tried to "discover" a box of ballots that they "forgot" to count on election day, the Supreme Court would have final say on the certification.
So mathematically and politically, there is essentially no possibility of your vote mattering in any significant election.
That being said, my friend promised me a beer if I voted for the tax in the referendum. I'm still undecided on whether to take up his offer or not.