Price rises out loud; bidders drop out once it passes their value. The last one standing wins, paying roughly the second-highest value.
Every bidder in this room privately values the lot differently. The same group of bidders, with the same private values, produces a different sale price and a different winner's payment depending only on the auction's rules — not on how much anyone actually wants the item.
Under the standard theoretical assumptions (independent private values, risk-neutral bidders), the English and Vickrey auctions yield the same expected revenue — both tend to land near the second-highest value. The Dutch auction, because it rewards strategic underbidding, typically yields somewhat less. Run the simulation repeatedly on each format to see this pattern emerge.
A 3D auction room where the same bidders, with the same private values, are run through English, Dutch and Vickrey auction rules — revealing how format alone changes the final price and who wins.
English and Vickrey auctions are strategically equivalent — both tend to land near the second-highest private value. Dutch auctions reward shaded, below-value bidding, which typically produces a lower sale price for the seller.
Pick a format, then watch paddles rise and fall as the price clock moves. Change bidder count and value spread to see how competition and dispersion affect the outcome, then compare formats directly.
William Vickrey won the 1996 Nobel Prize in Economics partly for showing that in a sealed-bid second-price auction, truthfully bidding your own value is always the optimal strategy — no guessing required.