@techreport{NBERw6988,
 title = "A Contribution to the Theory of Welfare Comparisons",
 author = "Martin L. Weitzman",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "6988",
 year = "1999",
 month = "February",
 URL = "http://www.nber.org/papers/w6988",
 abstract = {Using only information based on current directly-observable market behavior, the paper shows how to make rigorous dynamic welfare comparisons among economies or economic situations having arbitrarily-different endowments and technologies, but sharing a common dynamic preference ordering.  The correct answers to seemingly complicated questions, which intrinsically involve comparing wealth-like measures of dynamic well-being, can be translated isomorphically into a simple-minded story told in the familiar language of old-fashioned static consumer-welfare theory.},
}