Unobserved heterogeneity and censoring in the demand for health care.

In this paper we estimate a demand for private medical services equation based on the tradition of Grossman's model of demand for health using data for a panel of Spanish households. The econometric specification accounts for the censored nature of the data, which arises from no participation and infrequency of purchases, and the existence of unobserved heterogeneity, which arises from the non-observability of health states. Our evidence suggests that ignoring these features can have a significant impact on the size, sign and significance of the model estimates. The estimates for the participation and consumption processes also suggest that the deduction of expenditures on health care currently applicable in the Spanish tax system are positively associated to income and fertility.