With peak load pricing, the firm? Changes higher prices during peak periods, which increases produce surplus sense marginal cost does not very from. Period to period. Charges at all the times the higher price that reflects marginal, revenue and marginal cost during peak demand period to ensure a high price enough to cover marginal cost during all the periods. Attempts to increase economic efficiency by charging customer prices that vary with and are close to marginal cost of production during different time periods. Lower prices during peak periods, which increases capacity, utilization, and profits