"PHILOSOPHICALLY SPEAKING...":

When it is unlikely any individual vote will affect the outcome of an election, does one still have a moral obligation to vote? This piece, from the 1000-Word Philosophy project, explores the ethics of voting from a utilitarian or expected-value perspective.

"You often have some very good reason to act, even when doing that action only has a very small chance of creating a benefit, when the benefit is large enough. For example, in any particular car trip, a serious collision is unlikely, so fastening your child’s seatbelt only has a very small chance of making the difference about whether your child survives the trip—there probably won’t be a collision at all. Still, you ought to fasten the seatbelt, because of the small chance of major harm. ... For example, if there’s a 1% chance that buckling a seatbelt will save your child’s life, and the value of saving the child’s life is equal to ten million utils, and it costs you one util (say, in lost time) to buckle your child’s seatbelt, then the expected value of buckling your child’s seatbelt is equal to (1% of 10,000,000 utils) – 1 utils, i.e. 99,999 utils. Even though there is a small probability of having an effect, the value of the effect is so high that it’s worth doing. Let’s apply expected value to voting. There might only be a tiny chance that your vote will change who gets elected, but the net benefit of one candidate’s getting elected might be huge, for example in the billions of utils. Therefore, to decide whether you ought to vote, you must take into account the result of your vote’s changing the outcome, along with any other possible harms or benefits. ... But what if we were mistaken in our estimates? We could also be mistaken in our values: what we think is morally important. Most Americans have relatively little politically-relevant knowledge. It might be obligatory to abstain from voting if you don’t know enough about the election. By analogy, if you walk into a complicated factory and see a big, red, unlabeled button, and you don’t know what it does, don’t push the button. ... [But as with] every moral question, we must take seriously the possibility that expected consequences are not the only relevant moral consideration."
1000wordphilosophy.com/2020/06/28/ethics-and-the-expected-consequences-of-voting/