St. Paul, MN: University of Minnesota, Department of Applied Economics and International Science and Technology Practice and Policy (InSTePP), (2010, released 2011) and used in J.M. Alston, M.A. Andersen, J.S. James and P.G. Pardey. Persistence Pays: U.S. Agricultural Productivity Growth and the Benefits from Public R&D Spending. Natural Resource Management and Policy, vol. 34, New York, NY: Springer, 2010. Appendix Table 4.3.