The Rotterdam model, a complete consumer demand system, was fitted to personal consumption expenditure data for 1949-77 to study the interaction of consumer expenditures A full matrix of direct and cross price elasticities and income elasticities was estimated The 12 categories of expenditures were food at home, food away from home, alcohol and tobacco, clothing, housing, utilities, transportation, medical, durables, other nondurables, services, and miscellaneous