This book was written on the basis of courses taught by the author at the faculties of economics and applied mathematics of the Higher School of Economics in Moscow over the past four years. The book is addressed to undergraduate and graduate students of higher educational institutions studying economics, political science, management, applied mathematics. It is assumed that the reader owns the basics of mathematical analysis (differential and integral calculus), as well as the basics of probability theory. The book may also be of interest to graduate students (especially those who have not studied the subject before) and any reader wishing to prepare themselves to read international academic literature in economics or political science.