We estimate semiparametric Engel curves for rural Pakistan using a large household survey. This allows us to obtain consistent estimates of the effects of household size and composition on consumption patterns even when these demographic variables are correlated with an unknown function of income. The coefficients on the household composition variables are used to infer patterns of intrahousehold allocation. While there is little evidence of gender differences among children, adult males appear to consume more than adult females. Amongst males, workers consume more than dependents. There is no evidence of differential treatment of the elderly or of higher birth-order children. We identify substantial economies of size in food consumption. We also find that Engel curves for food, adult goods and child goods are quadratic logarithmic, which implies that some commonly used demand models are inappropriate.