structural:expansion
Relationship to democracy

The relationship between democracy and capitalism is a contentious area in theory and in popular political movements. The extension of adult-male suffrage in 19th-century Britain occurred along with the development of industrial capitalism and representative democracy became widespread at the same time as capitalism, leading capitalists to posit a causal or mutual relationship between them. However, according to some authors in the 20th-century, capitalism also accompanied a variety of political formations quite distinct from liberal democracies, including fascist regimes, absolute monarchies and single-party states. Democratic peace theory asserts that democracies seldom fight other democracies, but others suggest this may be because of political similarity or stability, rather than because they are "democratic" or "capitalist". Critics argue that though economic growth under capitalism has led to democracy, it may not do so in the future as authoritarian régimes have been able to manage economic growth using some of capitalism's competitive principles without making concessions to greater political freedom.

Political scientists Torben Iversen and David Soskice see democracy and capitalism as mutually supportive. Robert Dahl argued in On Democracy that capitalism was beneficial for democracy because economic growth and a large middle class were good for democracy. He also argued that a market economy provided a substitute for government control of the economy, which reduces the risks of tyranny and authoritarianism.

In his book The Road to Serfdom (1944), Friedrich Hayek (1899–1992) asserted that the free-market understanding of economic freedom as present in capitalism is a requisite of political freedom. He argued that the market mechanism is the only way of deciding what to produce and how to distribute the items without using coercion. Milton Friedman and Ronald Reagan also promoted this view. Friedman claimed that centralized economic operations are always accompanied by political repression. In his view, transactions in a market economy are voluntary and the wide diversity that voluntary activity permits is a fundamental threat to repressive political leaders and greatly diminishes their power to coerce. Some of Friedman's views were shared by John Maynard Keynes, who believed that capitalism was vital for freedom to survive and thrive. Freedom House, an American think-tank that conducts international research on, and advocates for, democracy, political freedom and human rights, has argued that "there is a high and statistically significant correlation between the level of political freedom as measured by Freedom House and economic freedom as measured by the Wall Street Journal/Heritage Foundation survey ".

In Capital in the Twenty-First Century (2013), Thomas Piketty of the Paris School of Economics asserted that inequality is the inevitable consequence of economic growth in a capitalist economy and the resulting concentration of wealth can destabilize democratic societies and undermine the ideals of social justice upon which they are built.

States with capitalistic economic systems have thrived under political regimes deemed to be authoritarian or oppressive. Singapore has a successful open market economy as a result of its competitive, business-friendly climate and robust rule of law. Nonetheless, it often comes under fire for its style of government which, though democratic and consistently one of the least corrupt, operates largely under a one-party rule. Furthermore, it does not vigorously defend freedom of expression as evidenced by its government-regulated press, and its penchant for upholding laws protecting ethnic and religious harmony, judicial dignity and personal reputation. The private (capitalist) sector in the People's Republic of China has grown exponentially and thrived since its inception, despite having an authoritarian government. Augusto Pinochet 's rule in Chile led to economic growth and high levels of inequality by using authoritarian means to create a safe environment for investment and capitalism. Similarly, Suharto 's authoritarian reign and extirpation of the Communist Party of Indonesia allowed for the expansion of capitalism in Indonesia.

The term "capitalism" in its modern sense is often attributed to Karl Marx. In his Das Kapital, Marx analyzed the " capitalist mode of production " using a method of understanding today known as Marxism. However, Marx himself rarely used the term "capitalism" while it was used twice in the more political interpretations of his work, primarily authored by his collaborator Friedrich Engels. In the 20th century, defenders of the capitalist system often replaced the term "capitalism" with phrases such as free enterprise and private enterprise and replaced "capitalist" with rentier and investor in reaction to the negative connotations associated with capitalism.