On setting prices and testing Cross-Subsidy with accounting data

Regulators are often faced with the challenge of both setting efficient prices and avoiding cross subsidy. Successful implementation of these goals requires estimates of both marginal costs and incremental costs. We present a methodology for estimating both marginal and incremental costs for postal products. The proposed algorithms combine micro-unit accounting data and econometric estimation of the cost structure. We apply the methodology to the U.S. Postal Service and produce estimates of marginal and incremental costs for eighteen postal products and incremental costs for another four groups of products.