World-systems theory (also known as world-systems analysis or the world-systems perspective) is a multidisciplinary, macro-scale 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-system" refers to the inter-regional and transnational division of labor, which divides the world into core countries, semi-periphery countries, and the periphery countries. Core countries focus on higher skill, capital-intensive production, and the rest of the world focuses on low-skill, labor-intensive production and extraction of raw materials. This constantly reinforces the dominance of the core countries. Nonetheless, the system has dynamic characteristics, in part as a result of revolutions in transport technology, and individual states can gain or lose their core (semi-periphery, periphery) status over time. This structure is unified by the division of labour. It is a world-economy rooted in a capitalist economy. For a time, certain countries 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.
Immanuel Wallerstein has developed the best-known version of world-systems analysis, beginning in the 1970s. Wallerstein traces the rise of the capitalist world-economy from the "long" 16th century (c. 1450–1640). The rise of capitalism, in his view, was an accidental outcome of the protracted crisis of feudalism (c. 1290–1450). Europe (the West) used its advantages and gained control over most of the world economy and presided over the development and spread of industrialization and capitalist economy, indirectly resulting in unequal development.
Though other commentators refer to Wallerstein's project as world-systems "theory", he consistently rejects that term. For Wallerstein, world-systems analysis is a mode of analysis that aims to transcend the structures of knowledge inherited from the 19th century, especially the definition of capitalism, the divisions within the social sciences, and those between the social sciences and history. For Wallerstein, then, world-systems analysis is a "knowledge movement" that seeks to discern the "totality of what has been paraded under the labels of the... human sciences and indeed well beyond". "We must invent a new language," Wallerstein insists, to transcend the illusions of the "three supposedly distinctive arenas" of society, economy and politics. The trinitarian structure of knowledge is grounded in another, even grander, modernist architecture, the distinction of biophysical worlds (including those within bodies) from social ones: "One question, therefore, is whether we will be able to justify something called social science in the twenty-first century as a separate sphere of knowledge." Many other scholars have contributed significant work in this "knowledge movement".
World-systems theory traces emerged in the 1970s. Its roots can be found in sociology, but it has developed into a highly interdisciplinary field. World-systems theory was aiming to replace modernization theory, which Wallerstein criticised for three reasons:
There are three major predecessors of world-systems theory: the Annales school, the Marxist tradition, and the dependence theory. The Annales School tradition (represented most notably by Fernand Braudel) influenced Wallerstein to focusing on long-term processes and geo-ecological regions as unit of analysis. Marxism added a stress on social conflict, a focus on the capital accumulation process and competitive class struggles, a focus on a relevant totality, the transitory nature of social forms and a dialectical sense of motion through conflict and contradiction.
Other influences on the world-systems theory come from scholars such as Karl Polanyi, Nikolai Kondratiev and Joseph Schumpeter (particularly their research on business cycles and the concepts of three basic modes of economic organization: reciprocal, redistributive, and market modes, which Wallerstein reframed into a discussion of mini systems, world empires, and world economies).
Wallerstein sees the development of the capitalist world economy as detrimental to a large proportion of the world's population. Wallerstein views the period since the 1970s as an "age of transition" that will give way to a future world system (or world systems) whose configuration cannot be determined in advance.
World-systems thinkers include Oliver Cox, Samir Amin, Giovanni Arrighi, Andre Gunder Frank, and Immanuel Wallerstein, with major contributions by Christopher Chase-Dunn, Beverly Silver, Volker Bornschier, Janet Abu Lughod, Thomas D. Hall, Kunibert Raffer, Theotonio dos Santos, Dale Tomich, Jason W. Moore and others. In sociology, a primary alternative perspective is World Polity Theory, as formulated by John W. Meyer.
World-systems analysis builds upon but also differs fundamentally from dependency theory. While accepting world inequality, the world market and imperialism as fundamental features of historical capitalism, Wallerstein broke with orthodox dependency theory's central proposition. For Wallerstein, core countries do not exploit poor countries for two basic reasons.
Firstly, core capitalists exploit workers in all zones of the capitalist world economy (not just the periphery) and therefore, the crucial redistribution between core and periphery is surplus value, not "wealth" or "resources" abstractly conceived. Secondly, core states do not exploit poor states, as dependency theory proposes, because capitalism is organised around an inter-regional and transnational division of labor rather than an international division of labour.
During the Industrial Revolution, for example, English capitalists exploited slaves (unfree workers) in the cotton zones of the American South, a peripheral region within a semiperipheral country, United States.
From a largely Weberian perspective, Fernando Henrique Cardoso described the main tenets of dependency theory as follows:
Dependency and world system theory propose that the poverty and backwardness of poor countries are caused by their peripheral position in the international division of labor. Since the capitalist world system evolved, the distinction between the central and the peripheral nations has grown and diverged. In recognizing a tripartite pattern in division of labor, world-systems analysis criticized dependency theory with its bimodal system of only cores and peripheries.
The best-known version of the world-systems approach was developed by Immanuel Wallerstein. Wallerstein notes that world-systems analysis calls for an unidisciplinary historical social science and contends that the modern disciplines, products of the 19th century, are deeply flawed because they are not separate logics, as is manifest for example in the de facto overlap of analysis among scholars of the disciplines. Wallerstein offers several definitions of a world-system, defining it in 1974 briefly:
a system is defined as a unit with a single division of labor and multiple cultural systems.
He also offered a longer definition:
...a social system, one that has boundaries, structures, member groups, rules of legitimation, and coherence. Its life is made up of the conflicting forces which hold it together by tension and tear it apart as each group seeks eternally to remold it to its advantage. It has the characteristics of an organism, in that it has a life-span over which its characteristics change in some respects and remain stable in others. One can define its structures as being at different times strong or weak in terms of the internal logic of its functioning.— 
In 1987, Wallerstein again defined it:
... not the system of the world, but a system that is a world and which can be, most often has been, located in an area less than the entire globe. World-systems analysis argues that the units of social reality within which we operate, whose rules constrain us, are for the most part such world-systems (other than the now extinct, small minisystems that once existed on the earth). World-systems analysis argues that there have been thus far only two varieties of world-systems: world-economies and world empires. A world-empire (examples, the Roman Empire, Han China) are large bureaucratic structures with a single political center and an axial division of labor, but multiple cultures. A world-economy is a large axial division of labor with multiple political centers and multiple cultures. In English, the hyphen is essential to indicate these concepts. "World system" without a hyphen suggests that there has been only one world-system in the history of the world.— 
Wallerstein characterises the world system as a set of mechanisms, which redistributes surplus value from the periphery to the core. In his terminology, the core is the developed, industrialized part of the world, and the periphery is the "underdeveloped", typically raw materials-exporting, poor part of the world; the market being the means by which the core exploits the periphery.
Apart from them, Wallerstein defines four temporal features of the world system. Cyclical rhythms represent the short-term fluctuation of economy, and secular trends mean deeper long run tendencies, such as general economic growth or decline. The term contradiction means a general controversy in the system, usually concerning some short term versus long term tradeoffs. For example, the problem of underconsumption, wherein the driving down of wages increases the profit for capitalists in the short term, but in the long term, the decreasing of wages may have a crucially harmful effect by reducing the demand for the product. The last temporal feature is the crisis: a crisis occurs if a constellation of circumstances brings about the end of the system.
In Wallerstein's view, there have been three kinds of historical systems across human history: "mini-systems" or what anthropologists call bands, tribes, and small chiefdoms, and two types of world systems, one that is politically unified and the other is not (single state world empires and multi-polity world economies). World systems are larger, and are ethnically diverse. Modernity is unique in being the first and only fully capitalist world economy to have emerged around 1450 to 1550 and to have geographically expanded across the entire planet, by about 1900. Not being political unified, many political units are included within the world system loosely tied together in an interstate system. Efficient division of labor is the unifying element of the different units, and it is also a function of capitalism, a system based on competition between free producers using free labor with free commodities, 'free' meaning available for sale and purchase on a market. More specifically, it can be described as focusing on endless accumulation of capital; in other words, accumulation of capital in order to accumulate more capital. Such capitalism has a mutually dependent relationship with the world economy since it provides the efficient division of labour, the unifying element of the world economy, through the process of accumulating wealth. Likewise, such capitalism is dependent on the world economy since the latter provides a large market and a multiplicity of states, enabling capitalists to choose to work with states helping their interests.
World-systems theory asks several key questions:
World-systems analysis argues that capitalism, as a historical system, has always integrated a variety of labor forms within a functioning division of labor (world economy). Countries do not have economies but are part of the world economy. Far from being separate societies or worlds, the world economy manifests a tripartite division of labor, with core, semiperipheral and peripheral zones. In the core zones, businesses, with the support of states they operate within, monopolise the most profitable activities of the division of labor.
There are many ways to attribute a specific country to the core, semi-periphery, or periphery. Using an empirically based sharp formal definition of "domination" in a two-country relationship, Piana in 2004 defined the "core" as made up of "free countries" dominating others without being dominated, the "semi-periphery" as the countries that are dominated (usually, but not necessarily, by core countries) but at the same time dominating others (usually in the periphery) and "periphery" as the countries dominated. Based on 1998 data, the full list of countries in the three regions, together with a discussion of methodology, can be found.
The late 18th and early 19th centuries marked a great turning point in the development of capitalism in that capitalists achieved state society power in the key states, which furthered the industrial revolution marking the rise of capitalism. World-systems analysis contends that capitalism as a historical system formed earlier and that countries do not "develop" in stages, but the system does, and events have a different meaning as a phase in the development of historical capitalism, the emergence of the three ideologies of the national developmental mythology (the idea that countries can develop through stages if they pursue the right set of policies): conservatism, liberalism, and radicalism.
Proponents of world-systems analysis see the world stratification system the same way Karl Marx viewed class (ownership versus nonownership of the means of production) and Max Weber viewed class (which, in addition to ownership, stressed occupational skill level in the production process). The core nations primarily own and control the major means of production in the world and perform the higher-level production tasks. The periphery nations own very little of the world's means of production (even when they are located in periphery nations) and provide less-skilled labour. Like a class system with a nation, class positions in the world economy result in an unequal distribution of rewards or resources. The core nations receive the greatest share of surplus production, and periphery nations receive the smallest share. Furthermore, core nations are usually able to purchase raw materials and other goods from non-core nations at low prices and demand higher prices for their exports to non-core nations. Chirot (1986) lists the five most important benefits coming to core nations from their domination of periphery nations:
According to Wallerstein, the unique qualities of the modern world system include its capitalistic nature, its truly global nature, and the fact that it is a world economy that has not become politically unified into a world empire.
Throughout the history of the modern world system, there has been a group of core nations competing with one another for access to the world's resources, economic dominance and hegemony over periphery nations. Occasionally, there has been one core nation with clear dominance over others. According to Immanuel Wallerstein, a core nation is dominant over all the others when it has a lead in three forms of economic dominance over a period of time:
Military dominance is also likely after a nation reaches these three rankings. However, it has been posited that throughout the modern world system, no nation has been able to use its military to gain economic dominance. Each of the past dominant nations became dominant with fairly small levels of military spending and began to lose economic dominance with military expansion later on. Historically, cores were found in Northwestern Europe (England, France, Netherlands) but were later in other parts of the world (such as the United States, Canada, and Australia).
Semi-peripheral nations are those that are midway between the core and periphery. Thus, they have to keep themselves from falling into the category of peripheral nations and at the same time, they strive to join the category of core nations. Therefore, they tend to apply protectionist policies most aggressively among the three categories of nations. They tend to be countries moving towards industrialization and more diversified economies. These regions often have relatively developed and diversified economies but are not dominant in international trade. They tend to export more to peripheral nations and import more from core nations in trade. According to some scholars, such as Chirot, they are not as subject to outside manipulation as peripheral societies; but according to others (Barfield), they have "periperial-like" relations to the core. While in the sphere of influence of some cores, semiperipheries also tend to exert their own control over some peripheries. Further, semi-peripheries act as buffers between cores and peripheries and thus "...partially deflect the political pressures which groups primarily located in peripheral areas might otherwise direct against core-states" and stabilise the world system.
Semi-peripheries can come into existence from developing peripheries and declining cores. Historically, two examples of semiperipheral nations would be Spain and Portugal, which fell from their early core positions but still managed to retain influence in Latin America. Those countries imported silver and gold from their American colonies but then had to use it to pay for manufactured goods from core countries such as England and France. In the 20th century, nations like the "settler colonies" of Australia, Canada and New Zealand had a semiperipheral status. In the 21st century, nations like Brazil, Russia, India, Israel, China, South Korea and South Africa (BRICS) are usually considered semiperipheral.
External areas are those that maintain socially necessary divisions of labor independent of the capitalist world economy.
Before the 16th century, Europe was dominated by feudal economies. European economies grew from mid-12th to 14th century but from 14th to mid 15th century, they suffered from a major crisis. Wallerstein explains this crisis as caused by the following:
As a response to the failure of the feudal system, Europe embraced the capitalist system. Europeans were motivated to develop technology to explore and trade around the world, using their superior military to take control of the trade routes. Europeans exploited their initial small advantages, which led to an accelerating process of accumulation of wealth and power in Europe.
Wallerstein notes that never before had an economic system encompassed that much of the world, with trade links crossing so many political boundaries. In the past, geographically large economic systems existed but were mostly limited to spheres of domination of large empires (such as the Roman Empire); development of capitalism enabled the world economy to extend beyond individual states. International division of labor was crucial in deciding what relationships exists between different regions, their labor conditions and political systems. For classification and comparison purposes, Wallerstein introduced the categories of core, semi-periphery, periphery, and external countries. Cores monopolized the capital-intensive production, and the rest of the world could provide only workforce and raw resources. The resulting inequality reinforced existing unequal development.
According to Wallerstein there have only been three periods in which a core nation dominated in the modern world-system, with each lasting less than one hundred years. In the initial centuries of the rise of Europe, Northwestern Europe constituted the core, Mediterranean Europe the semiperiphery, and Eastern Europe and the Western hemisphere (and parts of Asia) the periphery. Around 1450, Spain and Portugal took the early lead when conditions became right for a capitalist world-economy. They led the way in establishing overseas colonies. However, Portugal and Spain lost their lead, primarily by becoming overextended with empire-building. It became too expensive to dominate and protect so many colonial territories around the world.
The first nation to gain clear dominance was the Netherlands in the 17th century, after its revolution led to a new financial system that many historians consider revolutionary. An impressive shipbuilding industry also contributed to their economic dominance through more exports to other countries. Eventually, other countries began to copy the financial methods and efficient production created by the Dutch. After the Dutch gained their dominant status, the standard of living rose, pushing up production costs.
Dutch bankers began to go outside of the country seeking profitable investments, and the flow of capital moved, especially to England. By the end of the 17th century, conflict among core nations increased as a result of the economic decline of the Dutch. Dutch financial investment helped England gain productivity and trade dominance, and Dutch military support helped England to defeat France, the other country competing for dominance at the time.
In the 19th century, Britain replaced the Netherlands as the hegemon. As a result of the new British dominance, the world system became relatively stable again during the 19th century. The British began to expand globally, with many colonies in the New World, Africa, and Asia. The colonial system began to place a strain on the British military and, along with other factors, led to an economic decline. Again there was a great deal of core conflict after the British lost their clear dominance. This time it was Germany, and later Italy and Japan that provided the new threat.
Industrialization was another ongoing process during British dominance, resulting in the diminishing importance of the agricultural sector. In the 18th century, Britain was Europe's leading industrial and agricultural producer; by 1900, only 10% of England's population was working in the agricultural sector.
By 1900, the modern world system appeared very different from that of a century earlier in that most of the periphery societies had already been colonised by one of the older core nations. In 1800, the old European core claimed 35% of the world's territory, but by 1914, it claimed 85% of the world's territory, with the Scramble for Africa closing out the imperial era. If a core nation wanted periphery areas to exploit as had done the Dutch and British, these periphery areas had to be taken from another core nation, which the US did by way of the Spanish–American War, and Germany, and then Japan and Italy, attempted to do in the leadup to World War II. The modern world system was thus geographically global, and even the most remote regions of the world had all been integrated into the global economy.
As countries vied for core status, so did the United States. The American Civil War led to more power for the Northern industrial elites, who were now better able to pressure the government for policies helping industrial expansion. Like the Dutch bankers, British bankers were putting more investment toward the United States. The US had a small military budget compared to other industrial nations at the time.
The US began to take the place of the British as a new dominant nation after World War I. With Japan and Europe in ruins after World War II, the US was able to dominate the modern world system more than any other country in history, while the USSR and to a lesser extent China were viewed as primary threats. At its height, US economic reach accounted for over half of the world's industrial production, owned two thirds of the gold reserves in the world and supplied one third of the world's exports.
However, since the end of the Cold War, the future of US hegemony has been questioned by some scholars, as its hegemonic position has been in decline for a few decades. By the end of the 20th century, the core of the wealthy industrialized countries was composed of Western Europe, the United States, Japan and a rather limited selection of other countries. The semiperiphery was typically composed of independent states that had not achieved Western levels of influence, while poor former colonies of the West formed most of the periphery.
World-systems theory has attracted criticisms from its rivals; notably for being too focused on economy and not enough on culture and for being too core-centric and state-centric. William I. Robinson has criticized world-systems theory for its nation-state centrism, state-structuralist approach, and its inability to conceptualize the rise of globalization. Robinson suggests that world-systems theory doesn't account for emerging transnational social forces and the relationships forged between them and global institutions serving their interests. These forces operate on a global, rather than state system and cannot be understood by Wallerstein's nation-centered approach.
According to Wallerstein himself, critique of the world-systems approach comes from four directions: the positivists, the orthodox Marxists, the state autonomists, and the culturalists. The positivists criticise the approach as too prone to generalization, lacking quantitative data and failing to put forth a falsifiable proposition. Orthodox Marxists find the world-systems approach deviating too far from orthodox Marxist principles, such as by not giving enough weight to the concept of social class. The state autonomists criticize the theory for blurring the boundaries between state and businesses. Further, the positivists and the state autonomists argue that state should be the central unit of analysis. Finally, the culturalists argue that world-systems theory puts too much importance on the economy and not enough on the culture. In Wallerstein's own words:
In short, most of the criticisms of world-systems analysis criticize it for what it explicitly proclaims as its perspective. World-systems analysis views these other modes of analysis as defective and/or limiting in scope and calls for unthinking them.
One of the fundamental conceptual problems of the world-system theory is that the assumptions that define its actual conceptual units are social systems. The assumptions, which define them, need to be examined as well as how they are related to each other and how one changes into another. The essential argument of the world-system theory is that in the 16th century a capitalist world economy developed, which could be described as a world system. The following is a theoretical critique concerned with the basic claims of world-system theory: "There are today no socialist systems in the world-economy any more than there are feudal systems because there is only one world system. It is a world-economy and it is by definition capitalist in form."
Robert Brenner has pointed out that the prioritization of the world market means the neglect of local class structures and class struggles: "They fail to take into account either the way in which these class structures themselves emerge as the outcome of class struggles whose results are incomprehensible in terms merely of market forces." Another criticism is that of reductionism made by Theda Skocpol: she believes the interstate system is far from being a simple superstructure of the capitalist world economy: "The international states system as a transnational structure of military competition was not originally created by capitalism. Throughout modern world history, it represents an analytically autonomous level [... of] world capitalism, but [is] not reducible to it."
A concept that we can perceive as critique and mostly as renewal is the concept of coloniality (Anibal Quijano, 2000, Nepantla, Coloniality of power, eurocentrism and Latin America). Issued from the think tank of the group "modernity/coloniality" (es:Grupo modernidad/colonialidad) in Latin America, it re-uses the concept of world working division and core/periphery system in its system of coloniality. But criticizing the "core-centric" origin of World-system and its only economical development, "coloniality" allows further conception of how power still processes in a colonial way over worldwide populations (Ramon Grosfogel, "the epistemic decolonial turn" 2007):" by "colonial situations" I mean the cultural, political, sexual, spiritual, epistemic and economic oppression/exploitation of subordinate racialized/ethnic groups by dominant racialized/ethnic groups with or without the existence of colonial administration". Coloniality covers, so far, several fields such as coloniality of gender (Maria Lugones), coloniality of "being" (Maldonado Torres), coloniality of knowledge (Walter Mignolo) and Coloniality of power (Anibal Quijano).
New developments in world systems research include studies on the cyclical processes. More specifically, it refers to the cycle of leading industries or products (ones that are new and have an important share of the overall world market for commodities), which is equal to dissolution of quasi-monopolies or other forms of partial monopolies achieved by core nations. Such forms of partial monopolies are achievable through ownership of leading industries or products, which require technological capabilities, patents, restrictions on imports and/or exports, government subsidies, etc. Such capabilities are most often found in core nations, which accumulate capital through achieving such quasi-monopolies with leading industries or products.
As capital is accumulated, employment and wage also increase, creating a sense of prosperity. This leads to increased production, and sometimes even overproduction, causing price competition to arise. To lower production costs, production processes of the leading industries or products are relocated to semi-peripheral nations. When competition increases and quasi-monopolies cease to exist, their owners, often core nations, move on to other new leading industries or products, and the cycle continues.
Other new developments include the consequences of the dissolution of the Soviet Union, the roles of gender and the culture, studies of slavery and incorporation of new regions into the world system and the precapitalist world systems. Arguably, the greatest source of renewal in world-systems analysis since 2000 has been the synthesis of world-system and environmental approaches. Key figures in the "greening" of world-systems analysis include Minqi Li, Jason W. Moore, Andreas Malm, Stephen Bunker, Alf Hornborg, and Richard York.
Wallerstein traces the origin of today's world-system to the "long 16th century" (a period that began with the discovery of the Americas by Western European sailors and ended with the English Revolution of 1640). And, according to Wallerstein, globalization, or the becoming of the world's system, is a process coterminous with the spread and development of capitalism over the past 500 years.
Janet Abu Lughod argues that a pre-modern world system extensive across Eurasia existed in the 13th century prior to the formation of the modern world-system identified by Wallerstein. Janet Abu Lughod contends that the Mongol Empire played an important role in stitching together the Chinese, Indian, Muslim and European regions in the 13th century, before the rise of the modern world system. In debates, Wallerstein contends that Lughod's system was not a "world-system" because it did not entail integrated production networks, but it was instead a vast trading network.
Andre Gunder Frank goes further and claims that a global world system that includes Asia, Europe and Africa has existed since the 4th millennium BCE. The centre of this system was in Asia, specifically China. Andrey Korotayev goes even further than Frank and dates the beginning of the world system formation to the 10th millennium BCE and connects it with the start of the Neolithic Revolution in the Middle East. According to him, the centre of this system was originally in Western Asia.
Wallerstein's theories are widely recognized throughout the world. In the United States, one of the hubs of world-systems research is at the Fernand Braudel Center for the Study of Economies, Historical Systems and Civilizations, at Binghamton University. Among the most important related periodicals are the Journal of World-Systems Research, published by the American Sociological Association's Section on the Political Economy of the World System (PEWS), and the Review, published the Braudel Center.
Edythe E. Weeks asserts the proposition that it may be possible to consider, and apply critical insights, to prevent future patterns from emerging in ways to repeat outcomes harmful to humanity. (See Outer Space Development, Space Law and International Relations: A Method for Elucidating Seeds (Cambridge Scholars Publishing, 2012)). Her current research, as a Fulbright Specialist, further suggests that new territories such as the Antarctic Peninsula, Antarctica, the Arctic and various regions of outer space, including low Earth orbit, the geostationary orbit, Near Earth orbit are currently in the process of colonization. By applying lessons learned from our past, we can change the future towards a direction less likely to be widely criticized.