Procurement Contracts under Limited Liability.

I analyze in this paper procurement from agents protected by limited liability. I model limited liability as a verifiable bargaining tool that enables the agents to induce renegotiation when the contracted price does not cover the project's cost. I show that the determination of the optimal mechanism is based on a trade-off between playing informal rents and renegotiation costs. When the renegotiation costs are sufficiently large the first price auction is optimal among efficient mechanisms.