While theory strongly suggests that restricting development rights should reduce land prices, empirical evidence of this effect has been hard to obtain. Largely based on this difficulty, legislation governing the tax benefits that easement donors may receive is periodically challenged. We collect data on 131 land transactions in South Central Wisconsin, including 19 cases of development-restricted parcels. When we use the whole sample to estimate the impact of conservation easements, we replicate the results of Nickerson and Lynch [Nickerson, C.J., Lynch, 2001. The effect of farmland preservation programs on farmland prices. American journal of Agricultural Economics 83(2):341-351], finding a negative but statistically insignificant effect. However we then show that when the sample is appropriately restricted to a more homogenous group of land parcels, our ability to detect an effect increases dramatically. In particular, for vacant agricultural land we find a statistically significant negative impact of conservation easements that ranges up to 50% of land values. © 2008 Elsevier B.V. All rights reserved.