This book explores the rationality of consumption decisions arising from households comprising more than two persons in a context where distribution factors are observed. Distribution factors are defined as factors influencing the household decisions which are independent of the household members'' preferences and which do not modify the household budget constraint. Three theoretical results providing falsifiable restrictions on rationality are initially derived. A result on the number of household members influencing consumption decisions is also provided. These different results are then tested on a sample of polygamous households from Burkina Faso comprising two co-wives. Based on an analysis of the family context in Burkina Faso, potential distribution factors are proposed. The rationality of consumption decisions is then tested with these distribution factors and the theoretical results derived. The data are found to be consistent with rationality in a collective way, that is with each spouse influencing the consumption decisions.