Page:An Essay on the Principle of Population (1798).djvu/60

34 operation of many interrupting causes; such as, the introduction or failure of certain manufactures: a greater or less prevalent spirit of agricultural enterprize: years of plenty, or years of scarcity: wars and pestilence: poor laws: the invention of processes for shortening labour without the proportional extension of the market for the commodity: and, particularly, the difference between the nominal and real price of labour; a circumstance, which has perhaps more than any other, contributed to conceal this oscillation from common view.

It very rarely happens that the nominal price of labour universally falls; but we well know that it frequently remains the same, while the nominal price of provisions has been gradually increasing. This is, in effect, a real fall in the price of labour; and during this