Share vs envy for identical valuations (goods)

Dependencies:

  1. Fair division
  2. AnyPrice share
  3. Maximin share allocations
  4. PROPx
  5. EF1
  6. APS implies pessShare
  7. PROP implies APS

Consider a fair division instance having $n ≥ 3$ agents having equal entitlements and identical additive valuations, and $m = 2n-1$ goods, each of value 1. Let $A$ be an allocation where agent $n$ gets $n$ goods, and all other agents get 1 good each. Then this allocation is APS, MMS, and PROPx, but not EF1.

Proof

$1 = \MMS_i ≤ \APS_i ≤ v([m])/n = 2 - 1/n$. Hence, $APS_i = 1$, since the APS is the value of some bundle. Hence, $A$ is APS, MMS, and PROPx.

$A$ is not EF1 because the first $n-1$ agents EF1-envy agent $n$.

Dependency for: None

Info:

Transitive dependencies:

  1. /analysis/sup-inf
  2. /sets-and-relations/countable-set
  3. Bound on k extreme values
  4. Optimization: Dual and Lagrangian
  5. Dual of a linear program
  6. Linear programming: strong duality (incomplete)
  7. σ-algebra
  8. Set function
  9. Fair division
  10. AnyPrice share
  11. Proportional allocation
  12. Envy-freeness
  13. EF1
  14. Additive set function
  15. PROP implies APS
  16. Maximin share of a set function
  17. Maximin share allocations
  18. APS implies pessShare
  19. Submodular function
  20. PROPx