"Economists are indebted to Masanao Aoki. He has done an excellent job in bringing together a large amount of important material on stochastic dynamics, showing economists how to use it, and presenting it all in a clear and readable manner. The examples which he presents are interesting but surely only scratch the surface of what these tools can do to improve the realism and depth of economic modeling, macro and micro." Ken Judd, Hoover Institution, Stanford University