Vertical Enclosure: Vertical Integration and the Reluctance to Purchase from a Competitor
研究发现纵向一体化可能减少一体化企业的交易机会，导致其无利可图；当下游企业需在签约前承诺供应商时，一体化供应商会降低对竞争对手的供应质量，从而阻碍对手采购。
Vertical integration can reduce integrating firms' trading opportunities and, contrary to predictions of two‐firm models, this loss of trade can make integration unprofitable. If downstream units must commit to suppliers before contracting on the final terms of trade, then suppliers will have ex‐post monopoly power. This monopoly power reduces the quality that an integrated supplier will provide to its competitors. Expectations of this quality reduction can prevent firms from purchasing from an integrated supplier even though the supplier would be better off if it could commit to provide its downstream competitors with sufficient quality to retain their business.