Game theory

Vickrey Auction

A sealed-bid auction where the highest bidder wins and pays the second-highest bid.

Ask the Game theory assistant 1 min read · Updated September 9, 2026

Definition

Winner: i∗=arg⁡max⁡jbji^*=\arg\max_j b_j; payment: pi∗=max⁡j≠i∗bjp_{i^*}=\max_{j\ne i^*} b_j; all others pay 00.

With single-unit private values, truthful bidding bi=vib_i=v_i is weakly dominant.

Intuition

Because price is set by others, your bid only affects whether you win, not how much you pay — so truth-telling is optimal.

Incentive compatibility means bidders do not need to strategize over others' valuations.

Worked example

Values (10,7,4)(10,7,4): bidder 1 wins and pays 77, netting surplus 33.

Under symmetric IPV, expected revenue equals that of the first-price auction (Revenue Equivalence).

The math

The Vickrey auction is a special case of the VCG mechanism for a single indivisible good.

Generalizes to combinatorial settings as VCG, charging each winner their marginal externality on others.

Where it is used

Historical use in stamp auctions; conceptual basis for GSP in sponsored-search ads and many computerized markets.

Cornerstone example in mechanism-design teaching.

More in Game theory

Assembled from the ReLU.chat curated knowledge base. These explanations are concise on purpose; check the sources for anything important.