Economists must continually be concerned with the relations among theory, institutions, and facts and must regard every theory as subject to refutation. At every stage in this book, therefore, we have attempted to indicate which data are relevant and to distinguish between those ideas and theories that have been reasonably well tested and those that have not. A second major theme of this book concerns the relation between economic theory and economic policy; discussions of the uses and the limitations of economics. The third major feature of the book relates to the way we view modern students.

The book has been reviewed in every paragraph in an attempt to increase clarity; there is hardly a passage that has not undergone at least some small change.