The period of depression thus ensuing would continue until (1) the speculative advance in rents had been lost; or (2) the increase in the efficiency of labor, owing to the growth of population and the progress of improvement, had enabled the normal rent line to overtake the speculative rent line; or (3) labor and capital had become reconciled to engaging in production for smaller returns. Or, most probably, all three of these causes would co-operate to produce a new equilibrium, at which all the forces of production would again engage, and a season of activity ensue; whereupon rent would begin to advance again, a speculative advance again take place, production again be checked, and the same round be gone over. In the elaborate and complicated system of production which is characteristic of modern civilization, where, moreover, there is no such thing as a distinct and independent industrial community, but geographically or politically separated communities blend and interlace their industrial organizations in different modes and varying measures, it is not to be expected that effect should be seen to follow cause as clearly and definitely as would be the case in a simpler development of industry, and in a community forming a complete and distinct industrial whole; but, nevertheless, the phenomena actually presented by these alternate seasons of activity and depression clearly correspond with those we have inferred from the speculative advance of rent. Deduction thus shows the actual phenomena as resulting from the principle. If we reverse the process, it is as easy by induction to reach the principle by tracing up the phenomena. These seasons of depression are always preceded by seasons of activity and speculation, and on all hands the connection between the two is admitted—the depression being looked upon as the reaction from the speculation, as the headache of the morning is the reaction from the debauch of the night. But as to the manner in which the depression results from the speculation, there are two classes or schools of opinion, as the attempts made on both sides of the Atlantic to account for the present industrial depression will show. One school says that the speculation produced the depression by causing overproduction, and point to the warehouses filled with goods that cannot be sold at remunerative prices, to mills closed or working on half time, to mines shut down and steamers laid up, to money lying idly in bank vaults, and workmen compelled to idleness and privation. They point to these facts as showing that the production has exceeded the demand for consumption, and they point, moreover, to the fact that when government during war enters the field as an enormous consumer, brisk times prevail, as in the United States during the civil war and in England during the Napoleonic struggle.