Estimation of Compound Growth Rates for Non-Monotonic Situations through Nonlinear growth models using WebECGR package.

Abstract

Compound growth rate is widely employed in the field of Agriculture as it has important policy implications. Generally, this is computed by assuming that the path of response variable can be described by monotonically non-decreasing nonlinear growth models, like Malthus model and logistic model. However, in reality, data sets in agriculture need not always depict steady upward or downward movement over time, i.e. sometimes these are non-monotonic in nature. In such cases, it is not appropriate to employ above growth models. In this article, three nonlinear growth models, viz. over-damped, under-damped and critically-damped are considered, which have the capability to describe increasing and then decreasing or vice-versa type of behaviour of the response variable. The methodology to estimate compound growth rate by using these growth models is discussed. As it is very difficult to apply, an online user-friendly web-based application, viz. WebECGR package is developed. Finally, as an illustration, this package is employed for estimation of compound growth rate for India?s total lentil production data during the period 1980-81 to 2010-11.