Whereas consumer theory employs several different empirical specifications
for estimating indirect utility functions, producer theory has relied on the
Translog specification to estimate the indirect production function. In this
paper, we apply Lewbel's more general functional specification and
investigate its implications for the estimation of indirect production
functions in productivity analysis. An attractive feature of the Lewbel
model is that it nests both the Translog and the almost ideal supply system,
offering a method to assess the empirical validity of all three
specifications. Aggregate U.S. production data are used to examine the
performance of the three models in an empirical application.