The author analyses the relationship between regional disparities and economic efficiency. He also examines the efficiency of regional policy tools in the context of regional disproportions and economic efficiency. In the first part of the paper, the author discusses the main areas of controversy concerned with the regional distribution of business activity and its influence on economic growth. Then, using a graphic model to present the theory of endogenous growth and the New Economic Geography—and additionally considering social capital—Gajewski analyzes the economic effects of interregional transfers, subsidies for enterprises, investment in transport infrastructure and innovation policy. The author concludes that regional policy measures designed to support the regional diffusion of innovation and reduce its costs are the most effective instrument of regional policy, from the perspective of economic efficiency and the need to level out regional differences. Subsidies to enterprises seem to be the least beneficial, if not harmful, regional policy tool, Gajewski says. His research findings indicate that the use of various other regional policy instruments leads to an “equity-efficiency tradeoff,” or a conflict between economic and social objectives.