The authors have studied the world experience in forming public policy in the realm of R & D and mechanisms of its implementation in the early 21st century, which, in the opinion of many Russian and foreign scholars, is to become the century of the economy relying heavily on advanced science and state-of-the art technologies. The first part of the book deals with the policy of 30 countries with different levels of economic and technological development. The second part is devoted to the role of the state in ensuring the transition to knowledge-based economy, with emphasis on the problem, urgent for most of the countries, of enhancing the efficiency of budgetary expenditures. Universal and specific economic instruments of public R & D policy, tested by different countries, are analyzed. The third part describes the mechanisms of restructuring research institutions of the public sector with regard for the existing budget limitations and other problems related to the transition to knowledge-based economy. The analysis of the accumulated world experience makes it possible to work out the ways of improving the economic mechanism of the implementation of public R & D policy in Russia in the first decade of the 21st century.