He has also published articles in the philosophy of language, metaphysics, and social choice theory: in social choice, he first proved the result known today as Gibbard-Satterthwaite theorem,[2] which had been previously conjectured by Michael Dummett and Robin Farquharson.

[4] He received his BA in mathematics from Swarthmore College in 1963 with minors in physics and philosophy.

After teaching mathematics and physics in Ghana with the Peace Corps (1963–1965), Gibbard studied philosophy at Harvard University, participating in the seminar on social and political philosophy with John Rawls, Kenneth J. Arrow, Amartya K. Sen, and Robert Nozick.

The Gibbard's theorem assumes the collective decision results in exactly one winner and does not apply to multi-winner voting.

In social choice theory, the Gibbard–Satterthwaite theorem is a result published independently by Gibbard in 1973[12] and economist Mark Satterthwaite in 1975.

Gibbard argues that when we endorse someone's action, belief, or feeling as "rational" or warranted we are expressing acceptance of a system of norms that permits it.

[17] A recent review, including extensive citing of Gibbard's work above, is in the Stanford Encyclopedia of Philosophy (2015).