Looking Backward

Decision theory and theories of social choice are still relatively young. Game theory, which deals with related concepts, is young as well. Old would be, like algebra or classical physics.
Today's fun fact is the answer to the question, which states did the vote trading site R4C16 consider swing states in 2016? No peeking! For anyone who was paying attention to more important things this year, it goes like this:

The motto of the site was "Friends Don't Let Friends Vote for Trump."
Suppose you are Bob in a swing state and you want to vote for Gary Johnson as a protest vote because you are #NeverTrump. But you can not bring yourself to vote for Hillary. At least not in the normal way.
The site advises:
1) Decide Donald Trump must not be elected President.

2) Find a friend in a safe state who is voting for Clinton and ask them to vote for your candidate in exchange for you voting Clinton in a swing state.

3) Your swing state vote becomes a full vote against Trump by voting for Clinton, and your third party candidate still gets a vote.

And of course the site provided an app to help you find a "friend" in a safe state who would vote for Gary Johnson instead of that person's  preferred choice of Clinton.

Now the big problem for some theorists is the concept of voting for President as chiefly an expression of self, despite the privacy of the ballot. With no one watching, you somehow can not bring yourself to exercise the right to vote as wielding the small amount of political power you possess as a citizen.

Back to those so-called swing states:
Florida – 29 electoral votes
North Carolina – 15 electoral votes
Ohio – 18 electoral votes
Pennsylvania – 20 electoral votes
Texas – 38 electoral votes

Texas was included as a long shot, but possible. Which says a lot. So safe was the blue wall of Wisconsin and Minnesota and possibly Michigan, that if you paid any attention to this site, people in those three states might have been trading their Clinton votes away and voting for Gary Johnson! Which is just a hint of how totally ridiculous this whole vote swapping idea is.