Another purpose of the work is to examine seriatim the effects of different changes, to gauge the probability of their continuance, and to determine the resultant of all of them acting together. It is important to know under what conditions changes proceed at a normal rate, and when the standard of wages rises as it naturally should. As the actual rate of wages pursues its rising standard, but lags somewhat behind it, it is necessary to know what determines the interval between the two, and when the interval is normal. What is called "economic friction" is the cause of this interval and is an element that is amenable to law. There is to be studied, not only the friction which obstructs the action of natural forces, but positive perversions of the forces themselves. Of these the chief is monopoly; and its influence, its growth, the sources of its power, and its prospect of continuance have to be determined. The actual tendencies of the economic system are against it, and so--if we except a few monopolies created for special ends--are both the spirit and the letter of the civil law. In a country in which law held complete sway, all objectionable monopolies would be held in repression. In order to see how much economic forces can be made to do in this direction, the present work discusses railroads and their charges, and some of the practices of great industrial corporations, and tries to determine what type of measures a government should take in dealing with these powerful agents. In connection with monopoly and with the conditions of economic progress a study is made of trade unions, strikes, boycotts, and the arbitration of disputes between employers and employed, and also of the policy of the state in connection with them, and with money and protective duties. It is my belief that students should become acquainted with the laws of Economic Dynamics, and that they can approach the study of them advantageously only after a study of Economic Statics. The present work is in a form which, as is hoped, will make it available for use in class rooms, not as a substitute for elementary text-books, but as supplementary to them. It omits a large part of what such books contain, presents what they do not contain, and tries to be of service to those who wish for more than a single introductory volume can offer.