Edmund A. Estes

Tomato Wars: A Discussion of How International Trade, Structural Changes, and Competitiveness Affect the North American Produce Industry

The demand for a variety of fresh fruits and vegetables, including fresh market tomatoes, has increased significantly over the past decade because of greater convenience in use, improved selection, and rising health and diet concerns. As U.S. demand for tomatoes and other horticultural crops strengthens, inexperienced domestic and international suppliers believe they can compete effectively within U.S. markets. Free trade agreements have reduced monetary barriers to trade, but remaining impediments, such as institutional and competitive market constraints, represent significant challenges for southern U.S. growers. This paper discusses points addressed by VanSickle, Eastwood, and Woods concerning trade and horticultural market development.

On Variances of Conditional Linear Least-Squares Search Parameter Estimates

Among the class of models that are nonlinear in the parameters, some lend themselves to a simple estimation method requiring repeated application of linear least squares. However, there is confusion over methods for computing standard errors of such estimates. In this paper we define a simple method for estimating parameters of certain nonlinear models and clarify the interpretation of results. This method is based on conditional linear least squares. It has been used by Just (1974a,b, 1977) to estimate a generalized adaptive-expectations supply model. We show that a method commonly used to estimate asymptotic standard errors of such parameter estimates systematically overstates precision. Factors that affect the degree of overstatement are delineated. A method of calculating correct precision measures is contrasted empirically with the incorrect procedure.