(Un)bundling Public-Private Partnership Contracts in the Water Sector : Competition in Auctions and Economies of Scale in Operation

In public-private partnership transactions in the water sector, one of the alleged concerns is that there is little market competition at the auction stage. This paper casts light on a tradeoff between the competition effect at the auction level and potential economies of scale in service operation. If the authorities design a large-scale public-private partnership water transaction, it is expected to exploit operational scale economies. But the competition effect may have to be sacrificed. The paper shows a risk that the selection of the contract size could be a very restrictive condition that excludes many prospective bidders. Moreover, the paper quantifies the optimal size of public-private partnership contracts in the sector by estimating a cost function. The analysis shows that economies of scale exist but tend to diminish quickly as production increases. When the amount of water sold exceeds about 40 million