This work attempts to create a gravity model of the virtual water trade with
the presence of large quantities of zero trade flow observations. The measured
trade flows are the virtual water content of the crop commodities maize, rice,
and wheat, separated by green, blue, and grey virtual water content. The
model was fit using the Poisson pseudo-maximum likelihood (PPML)
estimator as supported by recent literature. The analysis resulted in no
definite conclusions about the gravity model or PPML as a method of fit.
Results of the modeling produce several errors conflicting with previously
established knowledge about gravity models and encourage further
investigation into methods of modeling the virtual water trade.
Hunter, Hope, "The Difficulties of Modeling Virtual Water Using Gravity Models" (2019). Senior Independent Study Theses. Paper 8747.
Virtual water, gravity model, water scarcity, agricultural trade
Bachelor of Arts
Senior Independent Study Thesis
© Copyright 2019 Hope Hunter