Structural Breaks, Yield Plateaus and Long Run Yield Trends in Indian Crop Sector

Abstract

There is increasing evidence across the world to support the existence of structural breaks, yield plateaus, and linear yield trends. In the Indian context, very few studies have addressed these issues, and most of them have concentrated only rice, wheat, and maize. Using advanced statistical methods, the present study attempts to identify structural breaks, traces the existence of yield plateaus and examines the prevalence of a linear form of yield growth in ten major crops and four major crop-groups in India for past four decades (1971–2013). Results indicate that five out of ten crops and three out of four crop-groups exhibit structural breaks, notably during the early 2000s. Majority of them have recorded increasing yield gains in the post-break period. Wheat and sugarcane have experienced yield deceleration since the 2000s, though not severe. Except for cotton, which had yield stagnation during the 1990s, none of them have shown yield plateaus. But, evaluating with alternate statistical specifications rules out such structural changes and yield transformations. It suggests linear yield trend as most prevalent, especially for crops, while exponential trend holds mostly for crop-groups. Hence, it calls for appropriate assumptions on existing yield trends in growth estimation.