Higgs, ZedThis dissertation combines theoretical analysis with economic experiments to advance our understanding of why people give. In particular, this dissertation focuses on the use of subsidies for giving---e.g., rebates and matches---as a tool for increasing charitable giving. The research included in this dissertation provides important guidance to charitable organizations seeking to design fundraisers optimally to maximize charitable receipts. Furthermore, this research also provides important guidance to policy-makers seeking to better understand the interplay between tax policy and charitable giving. The results of this dissertation can contribute to more effective fundraising campaigns and more efficient tax policy. Chapter 1 challenges the well-established result among existing experimental studies that donations are significantly more responsive to matches than to rebates. In previous experimental studies the budget sets available to subjects under rebates are constrained relative to those available under matches, biasing estimates of the rebate-price elasticity. We conduct a novel experiment that removes the constraint under rebates, producing equal budget sets for price-equivalent rebates and matches. Contrary to previous studies, we find dramatically smaller differences in donations under price-equivalent matches and rebates. More importantly, we find no statistical difference between our estimated rebate- and match-price elasticities. Furthermore, we show that the constraint under rebates affects the entire distribution of observed behavior, not only the behavior of individuals for whom the constraint is binding. This chapter contributes to theories of charitable giving and has important implications for tax policy. Chapter 2 studies how donor uncertainty affects their response to match subsidies in the context of charitable giving. It explores whether donors are responsive to exogenous changes in the probability of receiving a match. I develop a theoretical model of giving that incorporates uncertainty around matches. I demonstrate the model is capable of explaining the discrepancies in match-price elasticities of giving observed across previous field experiments and observational studies. I then derive testable hypotheses from the model, and design and run an economic experiment to test these hypotheses. The results of my experiment provide clear evidence that donors are responsive to changes in the probability of receiving a match. As a result, the same donor may respond differently to match subsidies depending on the setting. This work identifies an important aspect of donor decision making, contributing to a better understanding of why people give. It has important implications for theories of giving, the optimal design of fundraisers, and tax policy. Chapter 3 builds on Chapter 2 to continue studying how donor uncertainty affects their response to match subsidies in the context of charitable giving. It explores whether donors are responsive to endogenous changes in the probability of receiving a match resulting from changes in fundraiser characteristics. The results provide strong evidence supporting the notion that changes in fundraiser characteristics can affect donors' beliefs about the probability of receiving a match, in turn affecting their donation decisions and the observed response to match subsidies. The effectiveness of a match subsidy varies depending on the characteristics of the fundraiser, so that the optimal fundraising strategy varies across fundraisers. This chapter provides new guidance for fundraisers interested in increasing charitable donations through the use of match subsidies.enDissertationEconomicsEconomic theorySocial researchBehavioral EconomicsCharitable GivingExperimental Economics