Excerpt from David Harvey, “The Right to the City” (pp 5-6 in Rebel Cities, 2012):

The politics of capitalism are affected by the perpetual need to find profitable terrains for capital surplus production and absorption. In this the capitalist faces a number of obstacles to continuous and trouble-free expansion. If there is a scarcity of labor and wages are too high, then either existing labor has to be disciplined (technologically induced unemployment or an assault on organized working class power – such as that set in motion by Thatcher and Reagan in the 1980s – are two prime methods) or fresh labor forces must be found (by immigration, export of capital, or proletarianization of hitherto independent elements in the population). New means of production in general and new natural resources in particular must be found. This puts increasing pressure on the natural environment to yield up the necessary raw materials and absorb the inevitable wastes. The coercive laws of competition also force new technologies and organizational forms to come on line all the time, since capitalists with higher productivity can out-compete those using inferior methods. Innovations define new wants and needs, and reduce the turnover time of capital and the friction of distance. This extends the geographical range over which the capitalist is free to search for expanded labor supplies, raw materials, and so on. If there is not enough purchasing power in an existing market, then new markets must be found by expanding foreign trade, promoting new products and lifestyles, creating new credit instruments and debt-financed state expenditures. If, finally, the profit rate is too low, then state regulation of “ruinous competition;’ monopolization (mergers and acquisitions), and capital exports to fresh pastures provide ways out.”

David Harvey
“The Right to the City” in Rebel Cities
Verso, London 2012