Analysis of Growth and Instability in Rice Production of Odisha by Fitting Appropriate Statistical Models

Abstract

Agriculture in Odisha to a considerable extent means growing rice, the staple food of Odisha. The economic reforms in the 1991-92, affected the agriculture scenario of Odisha following which our study period (1970-71 to 2013-14) has been divided into pre-reform (1970-71 to 1991-92) and post reform (1992-93 to 2013-14) period. Attempts have been taken to make a comparative study of the growth rate and instability of area, production and yield of rice in the two periods. For studying the growth rate and instability, appropriate model which could best possibly describe the behavior of the phenomenon are fitted by applying spline regression technique with kink or knot placed at the year of transition from pre–reform period to post- reform period which is considered to be 1991- 92. The possible spline regression models which could fit very well to the area, production and yield of rice are identified from the scatter plot of the data. Then by help of residual diagnostics and model fit statistics, the best fit models are obtained. Using the best fit model, average growth rates of area, production and yield are found. Coefficient of variation is used as a measure of instability. The difference in growth rates from the prereform to post–reform period is found to be negative but non-significant in case of area, negative and highly significant in case of production and significantly positive in case of yield. The difference in coefficient of variation between the two periods is highly significant and positive only for yield. For area and production, it is negative and significant only in case of area.