the consideration of a perfect market structure. Hymer's main conclusion is that foreign direct investment can only succeed as long as there are market imperfections that can create advantages and conflicts: companies could reduce their competition by implementing foreign direct investment. In this way, companies can eliminate the arising conflicts in the market and benefit from their specific advantages. Hymer considered multinational firms to be better institutions than actual international markets in the process of stimulating business, and for information transmitting as well as price fixing. This was all elaborated by Dunning and Pitelis in the academic paper: "Stephen Hymer's Contribution to International Business Scholarship: An assessment and extension". In the analysis of the nature and causes of foreign investment, Hymer made a distinction between direct and portfolio investment. After ascertaining that differences in interest rates cause portfolio investments, but not direct investments, and that the industrial distribution of the latter is not significantly different from one country to another, as could be expected if their cause was solely differences in profitability, Hymer concluded that direct investments are capital movements associated to international operations of firms. Their goal is to keep control of production. This control allows either to suppress competition, or appropriate rents derived from advantages like skilled labour, cheap raw materials, access to capital markets or technology. Later, Hymer used Marxian language and concepts more explicitly. In a series of articles published in the 1970s, he considered the relationship between nation-states and multinational firms, detailing their role in the creation of an international division of labor. Hymer argued that this hierarchal division of labor was a macrocosm of the internal division of labor reproduced within the multinational corporation. Hymer did not believe that these firms had become more powerful than nation-states; instead, multinationals were firmly rooted in the major financial centers of the world, and they tended to reinforce existing geographic and spatial boundaries and dependencies. Papers and articles on this and various other topics articles were compiled by Hymer's graduate students from the New School for Social Research in The Multinational Corporation: A Radical Approach. Papers by Stephen Herbert Hymer, published by Cambridge University Press in 1979. Hymer's theories have strongly influenced other economists, like Cantwell and Dunning, and were elaborated by Hymer's dissertation advisor, Charles P. Kindleberger in American Business Abroad, series of lectures published in 1969. The latter played an important role in the posthumous