inkomstklasser

Inkomstklasser, or income classes, are categories used to classify individuals or households according to income, primarily annual gross income before taxes. They are used in sociology, economics, and public policy to study distribution, inequality, and to target policies. The most common approach is to divide a population into quantiles such as deciles or quintiles: for example, bottom 20 percent (lower income), middle 60 percent, top 20 percent. Some analyses use three broad classes (low, middle, high) or finer divisions.

In practice, income classes can be defined using gross or disposable income, and may be adjusted for household size and regional price levels. Analysts may also apply thresholds based on absolute amounts or relative shares of median income. Data sources include national statistical agencies and international organizations such as SCB in Sweden or OECD.

Applications include evaluating tax policy, welfare eligibility, and labor market outcomes, as well as research into consumption, savings, and social mobility. The concept is often used alongside other dimensions of socioeconomic status, such as education and occupation, to avoid reductionism.

Limitations: income is only one dimension of economic position; classifications are sensitive to methodology, currency and time, and may obscure within-class heterogeneity. In public discourse, terms like "low-income" or "upper-middle-income" can be normative as well as descriptive.

See also: social class, income inequality, decile, quintile, Gini coefficient.