Flexible but Parsimonious Demand Designs: The Case of Gasoline

In this paper, we consider expectations of the form E[log(y)|x] = a'log(x) as a good starting point for a more general analysis. We show why this naturally leads to the following flexible functional form E[y|x] = f(h(x)), where all functions are estimated by cubic splines. One of the main goals is to show that this estimator is straightforward to implement. We demonstrate the usefulness of the methods given in the paper by estimating gasoline demand from the 1994 RTECS data set, and in doing so, uncover interesting relationships of income and age on expected gasoline use.