Temporal Spillovers in Land Conservation

Temporal spillovers occur when a conservation program changes what happens to land outside the temporal window of the conservation contract. This may happen when conservation improves land so that returns to non-conservation uses are increased, or when landowners' preferences become more pro-conservation as they see land flourish under conservation, for example. These post-contract changes may occur on the extensive margin (acres of land conserved) or intensive margin (intensity of land in a given use). If temporal spillovers exist, benefits from conservation programs estimated by focusing solely on the effects that occur during the conservation contract will overstate or understate the true benefits of the program. I lay out a simple model of temporal spillovers. I test this model in the context of the United States Conservation Reserve Program (CRP). I use a pre-analysis sample specification step to choose counterfactual land most like the CRP land. On the extensive margin, I find that CRP causes some land to be 22-27% more likely to be farmed, potentially offsetting some environmental benefits. However, farmed ex-CRP land is slightly more likely to use a conservation practice. This is a mitigating factor on the intensive margin.