Into the Weeds: A Structural Model of Herbicide Demand and Glyphosate Resistance on U.S. Corn Farms

The first case of glyphosate resistant weeds was documented in 1998, two years after the commercialization of genetically engineered, herbicide tolerant (HT) corn and soybeans. Currently, over 14 resistant weed species affect U.S. crop production areas. This study uses a novel two-stage, structural model to derive cost functions for pre-emergent and postemergent herbicide use. The parameters of the structural model are estimated using censored nonlinear full information maximum likelihood. Control functions from firststage regressions account for endogeneity of farmers’ profit-maximizing decisions. The results of the analysis are used to determine the extent to which resistance has eroded the benefits associated with glyphosate applications in HT production systems. Our preliminary results suggest that glyphosate resistance may have decreased weed control by as much as 11 percentage points from 2005 to 2010.

[1]  J. MacKinnon.  Bootstrap Hypothesis Testing , 2007 .

[2]  Stephen B. Powles,et al.  Glyphosate-Resistant Crops and Weeds: Now and in the Future , 2009 .

[3]  Vangelis Tzouvelekas,et al.  Estimating population dynamics without population data , 2013 .

[4]  S. Yen.  Beverage consumption among US children and adolescents: full‐information and quasi maximum‐likelihood estimation of a censored system , 2002 .

[5]  Jeffrey M. Wooldridge,et al.  Quasi-maximum likelihood estimation and testing for nonlinear models with endogenous explanatory variables , 2014 .

[6]  Jorge Fernandez-Cornejo,et al.  Farm-Level Effects of Adopting Herbicide-Tolerant Soybeans in the U.S.A. , 2002, Journal of Agricultural and Applied Economics.

[7]  Glenn Fox,et al.  Damage Control and Increasing Returns , 1995 .

[8]  Jorge Fernandez-Cornejo,et al.  Technology Adoption and Off-Farm Household Income: The Case of Herbicide-Tolerant Soybeans , 2005, Journal of Agricultural and Applied Economics.

[9]  David Zilberman,et al.  The Econometrics of Damage Control: Why Specification Matters , 1986 .

[10]  L. Bauwens,et al.  Econometrics , 2005 .

[11]  I. Heap.  International survey of herbicide-resistant weeds , 1997 .

[12]  Takeshi Amemiya,et al.  The Maximum Likelihood and the Nonlinear Three-Stage Least Squares Estimator in the General Nonlinear Simultaneous Equation Model , 1977 .

[13]  Paul J Rathouz,et al.  Two-stage residual inclusion estimation: addressing endogeneity in health econometric modeling. , 2008, Journal of health economics.

[14]  Richard E. Quandt,et al.  The Estimation of Structural Shifts by Switching Regressions , 1973 .

[15]  John E. Franz,et al.  Glyphosate: A Unique Global Herbicide , 1997 .

[16]  A. Mishra,et al.  Are “Decoupled” Farm Program Payments Really Decoupled? An Empirical Evaluation , 2006 .

[17]  A. Ronald Gallant,et al.  Statistical Inference in an Implicit, Nonlinear, Simultaneous Equation Model in the Context of Maximum Likelihood Estimation , 1980 .

[18]  R. Heimlich.  Farm Resource Regions , 2000 .

[19]  L. Mitchell,et al.  Genetically Engineered Crops in the United States , 2014 .

[20]  Adrian Pagan,et al.  Econometric Issues in the Analysis of Regressions with Generated Regressors. , 1984 .

[21]  A. Havenner,et al.  The Economics and Econometrics of Damage Control , 1997 .

[22]  Jeffrey M. Woodbridge.  Econometric Analysis of Cross Section and Panel Data , 2002 .

[23]  R. Nehring,et al.  Pesticide Use in U.S. Agriculture: 21 Selected Crops, 1960-2008 , 2014 .