“So far as the individual capitalists are concerned, each takes the wage level for granted and attempts to do the best he can for himself. In introducing machinery he is therefore merely attempting to economize on his own wage bill. The net effect of all the capitalists’ behaving in this way, however, is to create unemployment which in turn acts upon the wage level itself. It follows that the stronger the tendency of wages to rise, the stronger also will be the counteracting pressure of the reserve army, and vice versa.”