Private parking slot sharing

This paper addresses the private parking slot sharing problem during regular working hours in a big city. Our results extend the existing market design theory so that money flow is allowed in the matching mechanisms. We consider two cases of money flow: (i) one agent who fails to exchange his parking slot can join the leasing mechanism as a lessor; and (ii) one agent who fails in parking slot exchange can always “transfer” (rent) his parking slots to the platform. Each agent is self-interested. We propose the (price-compatible) top trading cycles and deals (TTCD) mechanism for case (i) and the price-compatible top trading cycles and chains (PC-TTCC) mechanism for case (ii). Both mechanisms are effective in terms of the compatibility with money flow, agents’ welfare, and strategy-proofness. Our experimental results further show that the proposed mechanisms would result in remarkable social welfare, and (ex post) budget balance for the platform in a big city with large population. In some realistic settings, our proposed mechanisms can almost realize cost saving of 60% and make more than 50% of agents strictly better off. There is no private parking slot sharing in the benchmark case. Overall, this paper opens the door to the solutions of a host of price-compatible matching problems.