Shape Persistence in Elicited Subjective Crop Yield Probability Density Functions

The shape persistence of a crop yield probability density function (PDF) was studied by using two variants of the Visual Impact Method (VIM) to elicit subjective estimations by farmers. In one variant ten weights were used to describe the PDF and in the other variant the farmer chose the number of weights. Results were compared directly and by means of Weibull distributions fitting, with evidence being obtained in favor of methodological persistence and the equivalence of the two estimation methods.