The profit and loss of one yen bidding

The paper proves numerically the cause of occurrence of ‘one yen bidding’ which often occurs in the bid for contract of information processing in the public organization of Japan, and discusses the profit and loss of authority and bidder for that bidding. One yen bidding is the making a bid for contract with minimum bidding price one yen. It often occurs in the first bidding of a sequence of projects; project p divides into n projects p1,p2,...,pn which are strongly dependent on each other, and each one of them is contracted in order once a year. Therefore, in the following contracts, there are no competition among bidders, as the contractor of the first project p1 can take an advantageous position in relation to others. Though one yen bidder may lose in the first bidding, the deficit can be recovered by bidding with maximum bidding price in the following contracts. Game theory proves that one yen bidding is the optimal behavior for the bidder. By simulation with amount of contract, rate of interest and profit of bidder as parameters, the profit and loss of the one-yen bidder is shown. Finally, the paper defines the profit and loss of authority for contract, and analyses that value for the type of biddings of competition and coalition. [In Japanese.]