This paper explores the statistical properties of household consumption-expenditure budget shares distributions (HBSDs) defined as the share of household total expenditure spent for purchasing a specific category of commodities for a large sample of Italian households in the period 1989-2004. We...

By representing a system of budget shares as an approximate factor model we determine its rank, i.e. the number of common functional forms, or factors, spanning the space of Engel curves. Once the common factors are estimated via approximate principal components, we identify them by imposing...