Daniel Halperin (Harvard), Incentives for Conservation Easements: The Charitable Deduction or a Better Way, 74 Law & Contemp. Probs.29 (2011):

To give greater assurance that the public benefit of the gift will be consistent with the claimed deduction, the donee should be required to certify that it has selected the easement consistent with its mission and it has both the resources to manage and enforce the restriction and a commitment to do so. Moreover, it is inappropriate to measure the charitable deduction by the supposed loss in value to the donor from the imposition of the easement. The focus should be on actual benefit to charity. Therefore, eligibility for a charitable deduction for a conservation easement should be contingent on certification – by a public agency or, possibly, an IRS-accredited land trust – that the public benefit from the contribution is equivalent to the claimed deduction.

In fact, the recent changes to various tax-expenditure programs – placing caps on the expenditures and requiring the participation of expert agencies – indicates that Congress is less enamored than it once was with open-ended tax expenditures administered solely by the Treasury Department. This suggests a cap on tax credits for the contribution of conservation easements. Even if the program is open-ended, Congress should mandate participation of an expert agency such as the Bureau of Land Management, which is more capable of evaluating the public value of an easement.