Bt cotton has been cultivated in China for the past 10 years. Limitations of previous studies analyzing the impact of this technology are the short time period considered and lack of panel data. In this paper, we present findings from monitoring 150 Bt cotton farmers in 2002 and 2005....

How can we measure and compare the relative performance of production units? If input and output variables are one dimensional, then the simplest way is to compute efficiency by calculating and comparing the ratio of output and input for each production unit. This idea is inappropriate though,...