The Optimal Mechanism Designof Multi-unit Auction

Since the reform of the official car has been put on the government’s agenda,more and more exceed vehicle was cancelled.The official car auction is one of the main ways to deal with the exceed vehicles.In the official car auction,the case of the transaction price is lower than the actual value often appeared.The phenomenon not only causes the loss of state assets,but also makes the people to question the government’s credibility trigger social conflicts.So it is necessary to research on the mechanism of the official car auction,provide a theoretical foundation for solving this problem.This paper discusses the design of the optimal mechanism from two aspects of reserve price and the order of action.In this paper,the official car auction is abstracted into a heterogeneous multi-item auction model.In symmetric independent private value environment,sell two different items sequential with the first price.In the research of the auction order,analyze the bidder’s bidding strategy,calculate and compare the seller’s expected revenue of two auction orders.From the comparison results,we can know that the auction order is related to the influence factor of the two auctions,the importance of the optimal auction order is related to the value gap between objects and the number of bidders.In the research of the reserve price,we calculate expressions of the optimal reserve price from three perspectives under two kinds of payment commission methods.It concluded that the optimal reserve price of auction house and the optimal reserve price mutually agreed are not affected by commission payment method,but the seller’s optimal reserve price is affected by commission payment method.The optimal reserve price of the item that is sold secondly will be affected by the influence factor of the two auctions,but the first sold item’s optimal reserve price will not be affected.Therefore,in the official car auctions,choosing the auction order should be fully considered the impact factor between the two auctions,the value gap between objects and the number of bidders.Setting reserve price,firstly,we should consider the setting body,because the factors needed to consider not the same;secondly,we consider the impact factor between the two auctions,the payment method of commission and the number of bidders.The design of optimal auction mechanism needs to balance the interests of all parties,the seller should combine the actual situation to design the mechanism of their own needs.