Alan Ker, Chair presented at the University of Alberta, on "Technological Change in Crop Yields" on Nov. 26th...

Posted on Thursday, November 28, 2013

Technological changes in agriculture tend to alter the mass associated with a segment or subpopulation of the yield distribution as opposed to shifting the entire distribution upwards.  We propose modeling crop yields using mixtures with embedded trend functions to account for potentially different rates of technological change in different sub-populations of the yield distribution.  By doing so we can test some interesting and previously untested hypotheses about the data generating process of yields.  For example:  (1) is the rate of technological change equivalent across subpopulations; and (2) are the probabilities of sub-populations constant over time?  Our results -- technological change is not equivalent across subpopulations and probabilities have not changed significantly over time -- have implications for modeling yields.  While we consider the impacts for rating crop insurance contracts, accurate modeling of technological change is relevant to issues such as food sustainability, economic development, feeding a rapidly growing world population, biofuels markets and policy, and climate change.