Many minds have been at work trying to convince young people not to vote—it's a waste of time according to the economic logic of rational expectations.
The Economist ("Is it Irrational to Vote?") effectively rebuts much of this twaddle.
It's not irrational to vote when the stakes are high and the election is close, as this one surely is in many swing states.
Moreover, Kantian rationality asks us to act in ways that can be universalized. If everyone abstains from voting no one can be elected; democracy devolves into something else.
A colleague of mine adds a further idea: If you don't vote, you have no right to complain about anything later.
Finally, there is a virtue ethics notion that we are part of a community. Fulfilling our obligation to vote may take time and some expense, and true, some people free-ride. But that doesn't excuse me from acting in a way that supports a commitment to our joint democracy, which voting certainly is.
There are nuances I don't have time to address, including the argument that most people aren't well educated enough on the issues to cast a sensible ballot. Going down that road will I think lead to some sort of poll tax (in the form of a test before you can vote…. and who will make up the questions and grade the answers?).
And by the way: Which party has more to gain by disenfranchising voters by encouraging apathy?
As positive economics, the rational expectations model fails to predict how humans typically behave in Prisoner Dilemma and Ultimatum Games. The model omits important ideas about trust based on character, commitment, and moral sentiments that are important in the operation of markets and society. The idea that the same flawed model should now tell us how to behave normatively in voting is highly dubious.
Vote! And vote often.