World-systems theory (also known as world-systems analysis or the world-systems perspective) is a multidisciplinary approach to world history and social change which emphasizes the world-system (and not nation states) as the primary (but not exclusive) unit of social analysis. World-systems theorists argue that their theory explains the rise and fall of states, income inequality, social unrest, and imperialism.
The "world-system" refers to the inter-regional and transnational division of labor, which divides the world into core countries, semi-periphery countries, and periphery countries. Core countries have higher-skill, capital-intensive industries, and the rest of the world has low-skill, labor-intensive industries and extraction of raw materials. This constantly reinforces the dominance of the core countries. This structure is unified by the division of labour. It is a world-economy rooted in a capitalist economy. For a time, certain countries have become the world hegemon; during the last few centuries, as the world-system has extended geographically and intensified economically, this status has passed from the Netherlands, to the United Kingdom and (most recently) to the United States.
