Administrative Control, Buyer Concentration, and Price-Cost Margins
指出，买方集中度对卖方价格成本利润率的负向影响实际上源于行政控制，加入行政控制代理变量后，买方集中度的影响不再显著。
Steven H. Lustgarten (1975) and others have presented evidence that concentrated buyers lower the price-cost margins of sellers, but theory predicts that buyer concentration is positively correlated with administrative control of transactions. This paper shows that administrative control is responsible for the observed effect of buyer concentration. When a proxy for administrative control is included in Lustgarten's model, buyer concentration becomes insignificant. Copyright 1989 by MIT Press.