Lost and found: A natural field experiment on charitable donations, extinctions, and finance for conservation

This paper provides the first causal field evidence that loss aversion shapes pro environmental behavior in biodiversity conservation. Partnering with the Charles Darwin Foundation in the Galápagos, I exploit two rare real world events: the confirmed extinction of a tortoise subspecies and the rediscovery of another once believed extinct. These events motivated randomized email campaigns sent to 3983 prior donors in the Global North. Stratified randomization on past giving, nationality, and prior engagement supports internal validity, while real donors and real biodiversity outcomes preserve external validity. By focusing on actual donation behavior rather than intentions or stated willingness to pay, the study addresses a key gap in the literature. Results show that extinction framing raises the probability of donating from 1.2 percent to 2.1 percent (75 percent) and increases the average unconditional donation from USD 0.17 to USD 0.32 (about 88 percent), while rediscovery yields higher reported happiness and engagement. Together, the findings indicate complementary roles and possible long-term trade-offs, and show that real biodiversity changes can be harnessed to mobilize conservation finance and strengthen pro-environmental behavior.