Complementarity and substitutability in family members' time allocated to household production activities

This study reviews the concepts of complementarity and substitutability and the theoretical representations of these concepts used in demand analysis. It highlights difficulties encountered in empirical estimation of these relationships in the absence of adequate price data. A procedure for investigating these relationships in demand analysis under the assumption of constant relative prices is proposed. A model is formulated to test these relationships in family members' time allocated to household production activities. The data used in this analysis were collected in the Interstate Regional Research Project (NE-113), U.S.D.A. A simultaneous regression procedure is used. Results indicate that time of homemakers and their spouses are weakly complementary in several household maintenance activities, unpaid work, eating, shopping, recreation, organizational participation, physical and non-physical care of family members, and physical care of self. Homemaker's time in food preparation and spouse's time in physical care of self are found to be weakly substitutable. Relationships of substitutability are identified for each family member individually in his/her own discretionary activities. Discussion centers on implications of the model assumptions and use of residual analysis in applications other than demand analysis.Rosemary Key is an Assistant Professor, Department of Consumer Economics & Housing, 103 Martha Van Rensselaer Hall, Cornell University, Ithaca, NY 14853. In addition to time management, her research interests include the psychological foundations of managerial activity, and how time use impacts consumer behavior. She received her Ph.D. from The Ohio State University.