Game Theory & Decision

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Shapley Value (2-player)

Fair share of the total from a player's marginal contributions.

Formula

\phi_i = \tfrac{1}{2}(v(i) + [v(N) - v(j)])

Variables

φ_iPlayer i's fair share

vValue of a coalition

NGrand coalition

Example

Splits joint gains by each player's average contribution.

Did You Know?

The Shapley value, another Nobel-winning idea, is now used to explain individual feature impact in machine learning.

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