Spatial and Temporal Patterns of Rice Productivity in China and Brazil

This paper looks at differences in spatial and temporal variation of rice yields in China and Brazil. We find that rice yields in China have converged over time and that rice production has become more and more homogeneous. In contrast, rice yields in Brazil have diverged over time, primarily due to variations in upland rice yields. Three hypotheses are put forward to explain the different behaviour of rice yields in Brazil and China: (i) differences in production systems (i.e., irrigated in China versus upland in Brazil); (ii) changes in rainfall patterns and (iii) bias in agricultural R&D favouring irrigated rice. Our empirical analysis provides support to the first two hypotheses by establishing that upland rice is subjected to much greater variation in yields than irrigated rice and that changing rainfall patterns affect mostly upland rice. We also provide evidence of the bias towards irrigated systems by looking at the patterns of varietal release.