Social inequality occurs when resources in a given society are distributed unevenly, typically through norms of allocation, that engender specific patterns along lines of socially defined categories of persons. It is the differentiation preference of access of social goods in the society brought about by power, religion, kinship, prestige, race, ethnicity, gender, age, sexual orientation, and class. The social rights include labor market, the source of income, health care, and freedom of speech, education, political representation, and participation. Social inequality linked to economic inequality, usually described on the basis of the unequal distribution of income or wealth, is a frequently studied type of social inequality. Though the disciplines of economics and sociology generally use different theoretical approaches to examine and explain economic inequality, both fields are actively involved in researching this inequality. However, social and natural resources other than purely economic resources are also unevenly distributed in most societies and may contribute to social status. Norms of allocation can also affect the distribution of rights and privileges, social power, access to public goods such as education or the judicial system, adequate housing, transportation, credit and financial services such as banking and other social goods and services.
Many societies worldwide claim to be meritocracies—that is, that their societies exclusively distribute resources on the basis of merit. The term "meritocracy" was coined by Michael Young in his 1958 dystopian essay "The Rise of the Meritocracy" to demonstrate the social dysfunctions that he anticipated arising in societies where the elites believe that they are successful entirely on the basis of merit, so the adoption of this term into English without negative connotations is ironic; Young was concerned that the Tripartite System of education being practiced in the United Kingdom at the time he wrote the essay considered merit to be "intelligence-plus-effort, its possessors ... identified at an early age and selected for appropriate intensive education" and that the "obsession with quantification, test-scoring, and qualifications" it supported would create an educated middle-class elite at the expense of the education of the working class, inevitably resulting in injustice and – eventually – revolution. A modern representation of the sort of "meritocracy" Young feared may be seen in the series 3%.
Although merit matters to some degree in many societies, research shows that the distribution of resources in societies often follows hierarchical social categorizations of persons to a degree too significant to warrant calling these societies "meritocratic", since even exceptional intelligence, talent, or other forms of merit may not be compensatory for the social disadvantages people face. In many cases, social inequality is linked to racial inequality, ethnic inequality, and gender inequality, as well as other social statuses and these forms can be related to corruption.The most common metric for comparing social inequality in different nations is the Gini coefficient, which measures the concentration of wealth and income in a nation from 0 (evenly distributed wealth and income) to 1 (one person has all wealth and income). Two nations may have identical Gini coefficients but dramatically different economic (output) and/or quality of life, so the Gini coefficient must be contextualized for meaningful comparisons to be made.