Estimates of the Demand for Medical Care under Different Functional Forms.

We estimate price and income elasticities from a linear, log-linear, and the almost ideal demand model (with and without an adjustment for selectivity bias) in an effort to show that special attention should be paid to the underlying assumptions of consumer behaviour when estimating a medical care demand model. The literature on medical care utilization is extended by incorporating two major components of spending as separate demands in a system of medical care spending. We find that estimates of elasticities vary depending on the functional form of the estimating equation, thus questioning the usefulness for policy purposes of single estimates of elasticities. Copyright 1994 by John Wiley & Sons, Ltd.