This book provides a theory of trade between countries in at least one of which the pattern of competitive markets is disturbed by a powerful national labour union and in which, therefore, wage distortions are endogenous; the book then proceeds to re-examine the several comparative-equilibrium questions of conventional trade theory. In addition, several questions are confronted which can be posed only in the new framework.In Chapters II and III, two well-known models of production and trade are taken. In Chapter IV the analysis of Chapter II is reconsidered under the assumption that there is a strong labour union in each trading country. Chapters V-VII broaden the scope of analysis by allowing for capital accumulation and its interaction with union policies.