Kim, YounghoNature-based solutions for climate change mitigation and adaptation emphasize the restoration of natural infrastructure and the adoption of conservation practices in agriculture. Payment for ecosystem services (PES) programs play a key role in these efforts by offering financial incentives to farmers and landowners who adopt land use or management activities that provide environmental amenities and services for society. This dissertation consists of three chapters that examine the optimal design of PES programs and evaluate their performance in the context of climate change and environmental protection. The first chapter investigates whether PES programs contribute to climate change adaptation by reducing economic losses from extreme weather events. I evaluate the cost-effectiveness of the Conservation Reserve Enhancement Program (CREP) in the United States in mitigating flooded crop losses through the restoration of riparian buffers and wetlands. By leveraging variation in the timing of program introduction across counties in the Mississippi River Basin, I find that the introduction of CREP reduced both the number of flooded acres and the extent of damage on those acres. CREP also generated financial spillover effects on the federal crop insurance program, reducing indemnity payouts that would have otherwise been allocated to insured farmers. This study enhances our understanding of how PES programs promote sustainable agriculture and facilitate nature-based solutions for climate change adaptation. The second chapter examines the cost-effective structure of payments and penalties in PES programs, in collaboration with Erik Lichtenberg and David Newburn. The sustainability of ecosystem services programs is contingent on landowners’ compliance with the signed contracts after their initial participation. However, premature contract terminations are not uncommon, particularly when unexpected increases in crop prices lead to the removal of established conservation cover on agricultural land. In such cases, PES programs typically require participants to repay all payments received up to the date of contract termination (e.g., those in the US, the EU, Costa Rica, Mexico, Australia, and many other countries). This standard penalty structure is inefficient because it directly couples penalties with payments, increasing monotonically during the contract period. This study is the first to derive the optimal penalty structure that equals net environmental benefits for the remaining contract period, which decouples penalties from payments. A numerical policy simulation using integrated assessment models shows that the U.S. federal PES programs can substantially increase the environmental benefits by restructuring the current standard penalty. Importantly, the optimal penalty tends to decrease gradually during the contract period, providing credit to farmers for the ecosystem services generated prior to the contract termination. This finding has broad implications for restructuring PES programs in the U.S. and globally, and the study has been published in the Journal of Environmental Economics and Management. The third chapter examines the influence of U.S. federal agricultural conservation programs on the performance of emissions trading programs in promoting afforestation activities on agricultural land, in collaboration with Erik Lichtenberg, David Newburn, Haoluan Wang, and Derek Wietelman. Emissions trading programs, which pay for performance, have been advocated as flexible and efficient tools for achieving pollution reduction goals when evaluated in isolation. However, these programs often operate within a policy landscape dominated by conservation subsidy programs that pay for effort. We find that current federal conservation subsidies are so generous that they significantly crowd out water trading programs when both are in competition, although water trading programs would be effective in isolation. In addition, current carbon market payments for offsets are insufficient to make emissions trading programs more attractive compared to longstanding agricultural conservation subsidy programs. While prior studies have attributed low farmer participation in emissions trading programs to transaction costs and market uncertainty, our analysis suggests that even if these impediments are removed, competition with existing pay-for-effort programs would remain a significant barrier to expansion of emissions trading among agricultural producers. Therefore, the attractiveness and effectiveness of emissions trading programs for afforestation depend heavily on the presence and generosity of longstanding federal agricultural conservation subsidies.enDissertationEconomicsEnvironmental economicsAgriculture economicsAgri-environmental SchemeClimate ChangeLand ConservationNature-based SolutionPayment for Ecosystem Services Programs