Second-Best Mechanisms for Land Assembly and Hold-Out Problems

Land can be inefficiently allocated when attempts to assemble separately-owned parcels are frustrated by holdouts. Eminent domain can be used neither to gauge efficiency nor to determine adequate compensation. We characterize the least-inefficient class of direct mechanisms that are incentive compatible, self-financing, and protect the property-rights of participants. The second-best mechanisms, which we call Strong Pareto (SP), utilize a second-price auction among interested buyers, with a reserve sufficient to compensate fully all potential sellers, who are paid according to fixed and exhaustive shares of the winning buyer's offer. These mechanisms are strategy-proof (dominant-strategy incentive compatible), individually rational and self-financing. They generate higher social welfare in each problem compared to any other type of mechanism satisfying these properties.