Elicitation of subjective crop yield PDF [probability density functions]

Abstract

The aim of this research is to investigate the coherence and reliability of subjective crop yield probability density functions (PDF) elicited from a series of interviews carried out on a wide group of farmers. Three different elicitation techniques were used: the Two-Step PDF estimation method, the Triangular distribution and the Beta distribution. Subjects who were interviewed gave both estimates for point crop yield (mean, highest possible, most frequent and lowest possible) and for the PDF based on interval estimates. To evaluate persistence, two concepts were used: time persistence and methodological persistence. The results are deemed valuable in order to determine the level of trust in the techniques applied in obtaining data, and in their effectiveness in designing a farm decision support system (DSS).

Changes in Producers' Perceptions of Within-Field Yield Variability after Adoption of Cotton Yield Monitors

“…In general, this literature shows that mean yields that are subjectively elicited tend to coincide with the objective measures, but higher moments from the subjective temporal yield distribution (including temporal yield variability) tend not to be as accurate. Subjectively elicited or perceived temporal yield variability tends to be lower than objective estimates (Clop-Gallart and Juarez-Rubio, 2007;Egelkraut et al, 2006aEgelkraut et al, , 2006bPease, 1992), which implies an underestimation of temporal variability. This underestimation is consistent with what the behavioral finance literature calls "overconfidence" (see Smith and Mandac, 1995;Tversky and Kahneman, 1974).…”

“…A number of studies have investigated farmers' perceived temporal yield distributions (and temporal yield variability) (e.g., Bessler, 1980;Clop-Gallart and Juarez-Rubio, 2007;Egelkraut et al, 2006aEgelkraut et al, , 2006bGrissley and Kellogg, 1983;Pease, 1992;Smith and Mandac, 1995). Most of these studies, however, focus primarily on comparing a subjectively elicited temporal yield distribution with an objectively measured historical/temporal yield distribution (i.e., from county yields, historical individual yields from farm records, etc.).…”

“…(b 36 This method has also been used by Clop-Gallart and Juarez-Rubio (2007) to evaluate the reliability of subjectively elicited temporal crop yield probability distributions. The estimated mean and variance parameters from equations (6) and (7) are used in equations (2) and (3), respectively, to estimate beta shape parameters.…”

Microeconomics of Deficit Irrigation and Subjective Water Response Function for Intensive Olive Groves

“…There is limited published research on farmers' perceived expectations of temporal yield variability (e.g., [6]). Rejesus et al [7] studied the spatial dimensions of yield variability and subjective perceptions.…”

Subjective beliefs and decision making under uncertainty in the field

“…Attempts to elicit and incorporate farmers' subjective beliefs into models and analysis are fairly rare. Exceptions include studies that measure beliefs about yield loss due to crop disease or adverse weather (Carlson, 1970;Pingali and Carlson, 1985;Menapace et al, 2013), subjective yield, price and income expectations (Grisley and Kellogg, 1983;Clop-Gallart and Juárez-Rubio, 2007), subjective beliefs about optimal nitrogen applications (SriRamaratnam et al, 1987), and beliefs about weather impacts (Sherrick et al, 2000;Sherrick, 2002). These studies have relied on indirect methods of probability elicitation or fractile approaches, an exception being (Sherrick et al, 2000;Sherrick, 2002) which uses both a fractile and inverse CDF approach.…”