Marx predicted that competition among capitalists would grow so fierce that, eventually, most capitalists would go bankrupt, leaving only a handful of monopolists controlling nearly all production. This, to Marx, was one of the contradictions of capitalism: competition, instead of creating better products at lower prices for consumers, in the long run creates monopoly, which exploits workers and consumers alike. What happens to the former capitalists? They fall into the ranks of the proletariat, creating a greater supply of labor, a fall in wages, and what Marx called a growing reserve army of the unemployed. Also, thought Marx, the anarchic, unplanned nature of a complex market economy is prone to economic crises as supplies and demands become mismatched, causing huge swings in business activity and, ultimately, severe economic depressions.
The more advanced the capitalist economy becomes, Marx argued, the greater these contradictions and conflicts. The more capitalism creates wealth, the more it sows the seeds of its own destruction. Ultimately, the proletariat will realize that it has the collective power to overthrow the few remaining capitalists and, with them, the whole system.
The entire capitalist system—with its private property, money, market exchange, profit-and-loss accounting, labor markets, and so on—must be abolished, thought Marx, and replaced with a fully planned, self-managed economic system that brings a complete and utter end to exploitation and alienation. A socialist revolution, argued Marx, is inevitable.