The European Association for Environmental and Resource Economists (EAERE) has cited a research paper written by Economics ProfessorAnna Klis and her former doctoral student Godwin Ekpe as one of its top four publications of 2023.

Klis will be traveling in early July to the EAERE’s annual conference in Leuven, Belgium, to present the paper, titled “Spillover Effects in Irrigated Agriculture from the Groundwater Commons.”

The research was published in September in the peer-reviewed journal Environmental and Resource Economics, which is the EAERE’s official journal. Ekpe earned his doctorate in economics from NIU in May 2021. He currently works for JPMorgan Chase.

“There were 97 articles published in journal issues released last year, so to be one of the top four is amazing,” Klis said. “I’m thrilled to see our work recognized in this way. Godwin was my first ever Ph.D. advisee. We collaborated to expand on his original approach to this research, and he did the bulk of the empirical modeling, which was a heavy lift in terms data analysis.”

The economists also consulted with NIU Professor Megan Brown, who lent her expertise in hydrogeology to the project.

Klis and Ekpe (pictured below) focused their research on farmers’ water decisions in Colorado’s San Luis Valley, where water pumping fees are imposed. “We were able to examine how increasing the cost of pumping, via the fee, changed pumping behavior in an affected conservation district in comparison to areas where no fee was imposed,” Klis said.

Indeed, irrigators do respond to the pumping fees by decreasing their own groundwater use intensity and total acreage irrigated. But that’s far from the entire story, the researchers determined.

“We found that farmers in Colorado’s San Luis Valley not only consider their own pumping costs and water levels when deciding how much to irrigate, but also strategically react to their neighbors’ groundwater use and crop acreage decisions,” Klis said. “While farmers might not be able to directly see their neighbors’ total pumping or well levels, they can see things like what kind of crops neighbors are choosing and whether irrigation technologies are being employed.”

By incorporating water scarcity metrics and the impact of other irrigators into a theoretical model, Klis and Ekpe observed that a neighbor’s increased groundwater pumping significantly influenced a farmer’s own pumping behavior.

“We confirmed the existence of a spillover effect, where a neighbor’s increased groundwater pumping often had an even larger impact on a farmer’s own pumping decisions than the direct effect of their own well depth or costs,” Klis said.

“So, if a neighbor used more water, a farmer would respond by using even more water themselves, likely due to the shared aquifer and competition for the limited resource. Conversely, if a neighbor used less water, the farmer would respond by using less.”

The study underscores the importance of considering spillover effects between neighboring farmers when designing water conservation policies for sustainable management.

“Models ignoring these neighbor effects may underestimate the total impact of pumping fees or other conservation policies,” Klis said.

Water pumping fees are becoming more common in dry areas of the nation, particularly in the West. The implications of the research extend far beyond the San Luis Valley, offering valuable insights into the complex dynamics of resource management in agricultural communities.

By elucidating the nuanced relationships between individual decisions and collective outcomes, the study paves the way for more effective strategies for sustainable water use and cultivation practices in similar contexts worldwide.