Just-Pope production functions have been traditionally estimated by fe
asible generalized least squares (FGLS). This paper investigates the s
mall-sample properties of FGLS and maximum likelihood (ML) estimators
in heteroscedastic error models. Monte Carlo experiment results show t
hat in small samples, even when the error distribution departs signifi
cantly from normality, the ML estimator is more efficient and suffers
from less bias than FGLS. Importantly, FGLS was found to seriously und
erstate the risk effects of inputs and provide biased marginal product
estimates. These results are explained by showing that the FGLS crite
ria being optimized at the multiple stages are not logically consisten
t.