Protection and the Product Line: A Comment
调和了关于从价关税对进口质量构成影响的不同假设，证明该影响与市场结构无关，而取决于消费者是否只能购买一种品种。
This paper reconciles conflicting hypotheses about the effect of ad valorem tariffs on the quality composition of imports. Contrary to recent argument, it is shown that the effect is independent of market structure. The effect depends instead on whether or not consumers are restricted to purchasing only one variety. Copyright 1992 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.