This paper has three objectives: to review the historical contributions of the literature on structural models, to outline the problems of obtaining robust estimates of parameters, and to discuss how to improve the quality of results. The paper emphasizes applications in agricultural economics. The outline of the paper follows these objectives. I first discuss the nature of the contributions to the literature, but not the details of results. Then, I characterize the problems that have arisen in estimation. This naturally leads to a discussion of the consequences of the problems for empirical results and the impacts this has had on empirical econometrics. The final section looks to the future: how can we improve the quality of our work?