Terrance M. Hurley
University of Minnesota
Paul D. Mitchell
University of Wisconsin
George B. Frisvold
University of Arizona

The introduction and rapid adoption of herbicide-tolerant crops has renewed interest in better understanding the characteristics of herbicides and weed-management programs that are important to growers besides profitability. This study explores the importance of 13 characteristics, including characteristics that influence profitability, using data from a telephone survey of 1,205 corn, cotton, and soybean growers. We estimate a multivariate probit model to explore how the importance of these 13 characteristics varies with observable grower and farm-operation differences. Factor analysis based on the multivariate probit error correlations is conducted to gain further insight into the types of distinctions growers make between these 13 characteristics. Results show that growers rate characteristics such as consistency of control, crop safety, and family and employee health as very important more often than herbicide cost. The factor analysis suggests that health and environmental concerns, yield concerns, and herbicide-application concerns capture important unobservable preferences that influence grower decisions. These results imply that attempts to decompose the benefits of herbicide-tolerant crops by assigning unique values to specific characteristics that influence grower decisions can be confounded due to the difficulty in developing unique indirect measures of directly unobservable grower preferences.

Key words: Glyphosate, multivariate probit, principal components, Roundup Ready®, factor analysis.