Shapley value

A process for determining a fair allocation in a cooperative game. The Shapley value is computed by first determining what each player adds adding the difference between the pay-off to the coalition with the additiontd player and the pay-off to the coalition without. Second, the weighted sum of these pay-offs is computed with the weights being the probability that each coalition may form. The weighted sum is the Shapley value.

Reference: Oxford Press Dictonary of Economics, 5th edt.