in this journal, Hitiris [1979] provided the empirical examination of two propositions concerning the impact of protection and concentration on labour intensity. Both propositions tell us that labour intensity associates negatively with the degree of industry concentration and positively with the rate of protection. With this empirical analysis in the case of U. K. manufacturing industry, Hitiris concluded that both propositions are valid in actual data. His empirical study, however, is based upon incorrect theoretical considerations, and uses a misleading concept as a proxy for labour intensity. In this comment, we first make a clear demonstration of the continued validity of the Stolper-Samuelson theorem in spite of a monopoly situation. It follows that an a priori prediction between the level of protection and labour cost can be obtained. Secondly, we show that there is not always the consistency between labour intensity (kj) and labour cost (9Lj) in the presence of monopoly elements in the product markets. Relating to the first point, Hitiris argued that the Stolper-Samuelson theorem cannot be proven under monopoly conditions in the light of Melvin and Warne's results [1973]. In fact, they could not completely prove this theorem in that simplified form. In contrast to this conclusion, Batra [1973, Ch. 11] showed that the Stolper-Samuelson theorem is valid in spite of product market imperfections. Suppose the price of importables rises relatively to that of exportables. Then the following relationship holds if importables are relatively labourintensive.