Individual welfare is most naturally measured in terms of individual utility but this has the well-known disadvantage that utility levels of different consumers cannot be meaningfully compared. This difficulty is traditionally avoided by using various willingness-to-pay measures, such as compensating and equivalent variation. These measures are based on price changes. This paper develops alternative welfare measures using willingness-to-trade concepts as originally proposed by Dupuit (1844). These measures are based directly on commodity bundle changes. These welfare measures can be represented as integrals under certain inverse demand functions. <p>An important property of the proposed welfare measures studied here is that they can be meaningfully aggregated to form overall welfare measures. These measures in turn directly quantify a compensation criterion. It is shown that competitive prices provide a first-order approximation to the welfare measures. Furthermore a second-order approximation can be found by forming a suitable aggregation of the individual second-order effects. <p>Finally, it is shown that the representations for consumer welfare as integrals under inverse demand curves can be extended to the aggregate measures as well. This then provides a complete complement to traditional measures based on price changes.
