Price-cap regulation and inefficiency in relative pricing

The allocative efficiency properties of three price-cap schemes are compared. The scheme that uses lagged quantities in the price index and has a fixed cap works well when the firm is myopic but generates inefficient relative prices otherwise. With myopia prices are efficient and welfare is higher than with equal pricing, but the gain to the firm comes at the expense of lower consumer surplus. When the firm is not myopic pricing can be so inefficient that steady-state welfare is below the no-regulation level.