Block sourcing plus
研究一个无法直接价格歧视的买方如何满足对可分商品的需求，发现将区块采购与剩余供应定价结合总是优于单一策略，为两阶段合同提供了理论依据。
We study how a buyer unable to (directly) price discriminate should satisfy his demand for a divisible good, produced with increasing marginal cost. As expected, we find that dynamic pricing cannot, while auctioning contracts for lots (block sourcing) need not, lead to a higher buyer surplus than setting a price (classical monopsony). However, we show that the optimal combination of block sourcing with setting a price for the residual supply is always strictly superior. Thus, we provide a rationale for two-stage contracting even in the absence of uncertainty.