Disentangling Drivers of Rangeland Degradation: Herd Size versus Climate in Mongolia, 1985-2022

Relatore: Christopher B. Barrett (Charles H. Dyson School of Applied Economics and Management Cornell University)

  • Data: 29 settembre 2023 dalle 11:00 alle 12:00

  • Luogo: Aula III - Via Belle Arti, 41

Rangelands are the dominant land type on Earth and support the lives of some 2 billion people. Therefore it is crucial to understand the causes of rangeland degradation for both environmental and socioeconomic reasons. Using spatially disaggregated, nationwide time series data from Mongolia spanning 1985-2022, we empirically disentangle two hypothesized drivers of declines in rangeland biological productivity: herd size and climate change. We combine small area estimation and instrumental variables methods to causally identify the effects of herd size on summer grazing lands’ vegetation separately from the impacts of weather conditions on those same summer grazing lands. Exploiting seasonal variation in the geography of grazing, we use herd exposure to severe winter weather (dzuds) on winter grazing lands as an instrument for herd size. Larger herd sizes, higher temperatures and lower precipitation each negatively and significantly impact rangeland biological productivity. Climate changes’ impacts are an order of magnitude larger than those of herd size, however, albeit less so in cooler, higher-elevation areas.

Mario Mazzocchi