Conference Agenda

Are conservation policies detrimental to child health? Using rich household surveys from 2008 to 2021 and a unique database on Protected Areas (PAs) in Madagascar, this study examines the impact of PAs on infant anemia through a difference-in-differences estimation strategy. Results show that PAs reduce hemoglobin levels by1.8 g/L, a 2% decrease relative to pre-PA averages. Although this reduction appears modest, it leads to a 6 pp increase in the occurrence of infant anemia. This negative effect is driven by a rise in diarrhea and malaria, and partly by a decline in the consumption of iron-rich foods such as animal protein, despite improvements in access to drinking water and poverty reduction. These benefits are limited to multi-use PAs. These findings underscore the complex relationship between conservation policies and public health, highlighting the unintended trade-offs that can emerg

Environmental regulations aim to reduce pollution, yet they can also reshape ecological systems in ways that affect human health. We study China's ban on burning crop straw, introduced to reduce air pollution from agricultural fires. Combining nationwide inpatient records with the staggered rollout of the policy in a difference-in-differences design, we find that the ban raised hospitalizations for vector-borne diseases by about 50\% and inpatient spending by about 75\%. The evidence points to an ecological mechanism: crop residue left unburned provides habitat for insects and ticks that transmit disease, with effects concentrated among populations with greater agricultural exposure. We estimate the additional hospitalization burden at about \$223 million annually, offsetting close to 5\% of the health gains from cleaner air. The cost is not unavoidable. Where the ban was paired with subsidies for straw recycling, the increase in disease was substantially attenuated, suggesting that complementary residue-management policies can preserve air-quality benefits while reducing unintended health costs.

Migratory species play unique roles in ecosystems and have habitat needs that differ from non-migratory species. Although these differences present unique challenges for cost-effective conservation program design, relatively little empirical work has been done by economists to understand how budgets needed to protect species may differ based on whether the species migrates. A key point of differentiation is that, relative to traditional conservation planning problems focused on protecting sites based on site-specific benefits and costs but agnostic to site configuration, migratory species require a connected corridor. This weakest link characteristic adds an additional constraint to the planning problem. The cost of this constraint is an empirical question relevant for conservation budgets, which we explore here using data from Greater Yellowstone Ecosystem elk migrations in the United States. We use high resolution satellite data on crop type and density to capture the cost to landowners of having elk migrating through their land and GPS collar data showing site utilization to capture benefits to elk from different sites. Using a mixed integer-programming model, we select sites to target to maximize site benefits subject to a budget and corridor connectivity constraint. We then remove the connectivity constraint and rerun the model. We repeat for multiple budgets and calculate the cost of connectivity -- the difference in cost with and without the connectivity constraint, holding site utilization benefits constant. We repeat the process for four elk herds and, for a relatively low budget typical of conservation planning, calculate the minimum cost of connectivity across the herds to be approximately 82% greater than the cost for the case without the connectivity constraint. For two herds, the benefits associated with the focal budget can be obtained at about approximately zero cost when the connectivity constraint is removed. These extreme differences in costs with and without the connectivity constraint highlight the importance of migrations as a key aspect that can influence species conservation costs and support recent calls to develop new and innovative tools to support migratory species at reduced cost.

Despite global commitments to increase the area under conservation, rigorous evidence demonstrating the effectiveness of conservation areas is still lacking. This study presents experimental evidence on the impact of fish conservation zones on fish diversity and food security in a tropical freshwater ecosystem (the Xe Banghieng River, Lao PDR). We show that no-take areas increase ecosystem resilience as reflected in an increase in fish diversity (measured by both species and functional richness) four years after the impact of major floods. These improvements are achieved without compromising food security and are driven by increases in fish diversity across the distribution of extinction risk, including species with very low reproductive rates as well as those classified as vulnerable in the IUCN Red List. Our results support the use of no-take areas in freshwater ecosystems as an effective conservation strategy.