Skip to content

Main content

Shapley One Coalition Marginal Term Tool

One Shapley summand with weight |S|!(n-|S|-1)!/n!, evaluated through a binomial-product denominator.

Loading tool…

Description

Return withValue minus withoutValue and weight 1/[players × binomial(players-1, coalitionSize)], then their product.

Cooperative-game calculations compare coalition values, allocated payoffs or voting weights. A single coalition term or party share can be useful in a larger calculation without establishing a complete power index, core allocation or bargaining solution.

Return withValue minus withoutValue and weight 1/[players × binomial(players-1, coalitionSize)], then their product.

When to use this tool

Use Shapley One Coalition Marginal Term when you need one explicit coalition, voting or bargaining term.

How to use the tool and how it works

  1. Enter players, coalitionSize, withoutValue, withValue. Use the units and conventions below.
  2. Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
  3. Read marginalContribution, permutationWeight, weightedContribution. Use the output convention below.

Require players 1-100 and coalitionSize 0 through players-1. Return withValue minus withoutValue and weight 1/[players × binomial(players-1, coalitionSize)], then their product.1

Input fieldMeaning and unitsAccepted input
playersPlayersRequired. Safe integer; minimum 1; maximum 100.
coalitionSizeCoalition SizeRequired. Safe integer; minimum 0.
withoutValueWithout ValueRequired. Finite number.
withValueWith ValueRequired. Finite number.
Output fieldInterpretationReturned shape
marginalContributionMarginal ContributionRequired. Finite number.
permutationWeight1/[n·binomial(n-1,k)] for this one subset, not an aggregate over all subsets of size k.Required. Finite number.
weightedContributionWeighted ContributionRequired. Finite number.
json
{
  "input": {
    "players": 4,
    "coalitionSize": 1,
    "withoutValue": 10,
    "withValue": 22
  },
  "output": {
    "marginalContribution": 12,
    "permutationWeight": 0.08333333333333333,
    "weightedContribution": 1
  }
}

Limitations and assumptions

  • This is one coalition's Shapley contribution, not the sum over coalitions or a complete allocation. Values must represent the same coalition with and without the focal player.
  • Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
  • Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.

Alternative or Complementary methods

Evaluate all required coalitions and allocation constraints for the chosen solution concept. Keep payoff units, quota conventions, feasibility and normalization explicit.

References

  1. Calculation and input contract: game-theory/shapley-one-coalition-marginal-term — tool.io

Similar or alternative tools