This note studies the optimal demand commitment in a uniform-price procurement auction, within the class of linear schedules.

When the auctioneer (which is the buyer) can commit ex ante to the slope of demand, the equilibrium is a Pareto improvement relative to the simultaneous benchmark.

This is because the sellers’ slope choice generates positive externalities on the buyer, so when committing, the buyer has incentives to choose a steeper slope.

As a result, commitment mitigates the supply reduction due to market power: the equilibrium has both a higher price and higher quantity, so that both the buyer and the sellers are strictly better off.