Richard V. Burkhauser, James T. Wilkinson, The Effect of Retirement on Income Distribution: A Comprehensive Income Approach, The Review of Economics and Statistics, Vol. 65, No. 4 (Nov., 1983), pp. 653-658

The household production literature emphasizes that technical or biological processes condition input selection by households in their production activities, along with prices and income. Exogenous variations in health, to the extent that they are perceived by individuals (heterogeneity), lead to correlations between inputs and health outcomes that cannot be used to derive causal conclusions. Therefore, estimates of health technology must be obtained from a behavioral model in which health inputs are themselves choices. Consistent estimates are reported of the effect of endogenous inputs, such as medical care, smoking, and fertility, on birth weight and fetal growth in the presence of health heterogeneity.

[Forward and spot exchange rates are modelled as an unrestricted bivariate autoregression from weekly data on the New York foreign exchange market for June, 1973 to April, 1980. The null hypothesis that the forward exchange rate is an unbiased estimate of the corresponding future spot exchange rate is tested by means of a nonlinear Wald test and is rejected for all six currencies considered. The results cast doubt on a central assumption in many current models of exchange rate behavior.]