Discriminatory Price Auctions in Electricity Markets: Low Volatility at the Expense of High Price Levels

A pay-as-offered or discriminatory price auction (DPA) has been proposed to solve the problem of inflated and volatile wholesale electricity prices. Using the experimental method we compare the DPA with a uniform price auction (UPA), strictly controlling for unilateral market power. We find that a DPA indeed substantially reduces price volatility. However, in a no market power design, prices in a DPA converge to the high prices of a uniform price auction with structural market power. That is, the DPA in a no market power environment is as anti-competitive as a UPA with structurally introduced market power.