The monograph is devoted to an in-depth and multithreaded analysis of the effects of trade integration of countries with different levels of economic development. It presents the results of research on the profitability of international trade liberalization from the perspective of a less developed country. An example is the North American Free Trade Agreement – unique in the world due to the asymmetry of development of the economies of the participating countries. An assessment of the impact of integration on Mexico was presented based on extensive literature and empirical studies. The publication is one of the first scientific studies in Poland presenting such a comprehensive investigation of economic integration processes on the North American continent.