英文文献：Land Trusts Policy: Is It Socially Optimal?-土地信托政策:社会最优吗?私有部门(主要是土地信托)在土地保护方面的显著增长，是由于一些补贴这类活动的政策
英文文献作者：Farja, Yanay,Rausser, Gordon C.
英文文献摘要：
The impressive growth in land conservation by the private sector, primarily by land trusts, has resulted from a number of policies that subsidize such activity. These include federal income and estate tax benefits, and state income and property tax benefits. We model the equilibrium in the private land conservation market and the social welfare maximization problem of the government. We estimate the supply of conservation easements in the San Francisco Bay Area counties. Our results show that conservation easements are own price inelastic, but nevertheless are sensitive to the opportunity cost of land. For a simultaneous equation model, the spillover effect of easements on the value of other properties is found to be positive and significant. A possible equity implication is the barriers to entry facing low-income individuals in the housing market.

其中包括联邦收入和遗产税优惠，州收入和财产税优惠。我们建立了私有土地保护市场的均衡模型和政府的社会福利最大化问题。我们估计了旧金山湾区各县保护地役权的供应情况。结果表明，保护地役权的价格是无弹性的，但对土地的机会成本是敏感的。在联立方程模型中，地役权对其他财产价值的溢出效应为正且显著。一个可能的公平性暗示是低收入个人在住房市场面临的进入壁垒。