中文摘要：

在界定协议供地政策和招拍挂供地政策含义和建立分析假说的基础上，首先对2种供地政策对市场结果的影响进行了比较分析。分析的结果是：相对于招拍挂供地政策形成的市场价格而言，协议出让引起了大量的土地短缺。接着分析了2种供地政策对经济福利的影响，与招拍挂供地政策相比，协议供地政策对土地资源配置的效率低下，存在着经济福利的无谓损失。最后，用现实数据对前文的经济学分析进行了检验，检验的结果与前文的分析是一致的。

英文摘要：

Based on explaining meanings of land supply policy of public bidding, auction, signboard listing and agreement as well as building analysis hypothesis, the author firstly analyzed the effects of the policies on land market results, which leads to a conclusion that compared with the land market price under the policy of public bid- ding, auction and signboard listing, agreement price brings on a large shortage of land resources. Then, the author interpreted the effects of these two policies on economic welfare, and takes for that compared with another policy, the land supply policy of agreement produces low efficiency on land resources allocation and deadweight loss of eco- nomic welfare. Finally, the author also checked up the analysis with real data, which result was consistent with the analysis.