First published in 1952, as the second edition of a 1949 original, this book contains a discussion of the role of expectation in relation to the workings of the economy. For the purposes of the discussion, expectation is defined as the act of creating imaginary situations, of associating them with named future dates, and of assigning to each of the hypotheses thus formed a place on a scale measuring the degree of belief that a specified course of action will make this hypothesis come true. The text also contains appendices and a detailed index. This book will be of value to anyone with an interest in economic theory and methods of dealing with economic uncertainty.