The whole argument of this book may be summed up in the statement that in studying the effects of any given economic proposal we must trace not merely the immediate results but the results in the long run, not merely the primary consequences but the secondary consequences, and not merely the effects on some special group but the effects on everyone. It follows that it is foolish and misleading to concentrate our attention merely on some special point—to examine, for example, merely what happens in one industry without considering what happens in all. But it is precisely from the persistent and lazy habit of thinking only of some particular industry or process in isolation that the major fallacies of economics stem. These fallacies pervade not merely the arguments of the hired spokesmen of special interests, but the arguments even of some economists who pass as profound.