In a large-scale natural field experiment, we partnered with a micro-lending company in Kyrgyzstan that asked over 180,000 of its clients for donations to social projects as a form of corporate philanthropy. In a 2×2 design, we explored two main (pre-registered) hypotheses about giving by the poor. First, based on a conjecture that poor are more price sensitive than the rich and in contrast to previous studies, we hypothesize that matching incentives induce crowding in of out-of-pocket donations. Second, we hypothesize that our population cares about their proximity to the charitable project. We find evidence in favor of the former hypothesis but not the latter. Previous studies of charitable giving focus on middle- or high-income earners in Western countries, neglecting the poor, although the lowest income groups are often shown to contribute substantial shares of their income to charitable causes. Our results challenge the evidence in the extant literature but are in line with our theoretical model. The implications for fundraising managers are that the optimal design of fundraising campaigns crucially depends on the targeted groups, and that donation matching is successful in stimulating participation in poorer populations.