Economists use game theory to overcome misinformation about fungicide resistance

Adapting to resist our most effective fungicides, fungal pathogens are a threat to important global crops like wheat and grapes. Newly published research from economists at Washington State University underlines the need for education to combat misinformation and incentivize farm practices aimed at halting fungicide resistance.

Ana Espinola-Arredondo
Ana Espinola-Arredondo is the newest co-editor of the journal Environmental and Resource Economics.

In “Fungicide resistance and misinformation: A game theoretic approach,” a new article published by the Canadian Journal of Agricultural Economics, Chelsea Pardini, a WSU alumna and postdoctoral scholar at Stanford University, and Ana Espínola-Arredondo, professor and associate director of the School of Economic Sciences, used game theory to examine how farmers make decisions that affect the fungal landscape.

There is no current system to monitor and predict resistance, which is often only identified after an outbreak, and farmers may not always have accurate knowledge of fungicide resistance.

“Misinformation can cause farmers to use more spray, exacerbating fungicide resistance,” Espínola-Arredondo said.

One proposed approach to prevent resistance is rewarding beneficial practices. Farmers who voluntarily restrict their fungicide use, working against resistance by lowering selection pressure, would be compensated for their loss in yields and profits by farmers who aren’t restricted.

Game theory helps scientists understand how people make choices when faced with the decisions of others. Using mathematical models, authors simulated scenarios involving two groups of farmers, one receiving compensation, the other paying, theorizing the distorting effect of misperceptions on their use of fungicides.

“The objective was to find a mechanism that induces both groups to reduce their use of fungicide in order to ameliorate the negative effects of resistance,” Espínola-Arredondo said.

While informed farmers lowered their use to a level that served the common good, misinformed farmers needed more inducements to do so.

The scientists found that misinformation makes it more costly to enact compensation mechanisms that incentivize farmers who use fungicide in ways that prevent resistance.

“Our findings shed light on the strategic behavior of farmers when they face fungicide resistance,” Espínola-Arredondo said.

The authors offer recommendations for better incentives that could motivate growers to stop over-using fungicide. The results also highlight the importance of developing educational programs to reduce misinformation about fungicide resistance.

“We hope that more policies designed to tackle fungicide resistance consider tools that induce cooperation among farmers,” Espínola-Arredondo said.

Pardini and Espínola-Arredondo’s research was part of the Fungicide Resistance Assessment, Mitigation, and Extension (FRAME) Networks project for wine, table, and raisin grapes led by WSU Professor Michelle Moyer.

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