The Hamilton method for estimating CPI bias is simple, intuitive, and has been widely adopted. We show that the method conflates CPI bias with variation in cost-of-living across income levels. Assuming a single price index across the income distribution is inconsistent with the downward sloping...

An additive partially linear regression model is used to estimate non-parametrically the effects of total expenditure and age in the context of Engel curves and to investigate the specification and welfare interpretation of the age effects in parametric models of consumer behaviour. Empirical...