How much money does a couple save on consumption by living together versus living apart? What percentage of a married couple's expenditures are controlled by the husband? We propose a model of household behavior that permits identification and estimation of concepts like these. We model households in terms of the utility functions of its members and a consumption technology function. We demonstrate generic identification of the model, and hence of equivalence scales, consumption economies of scale, household members' bargaining power and other related concepts. Our empirical application of the model uses data from the UK Family Expenditure Surveys.