Economic inequality (also described as the gap between rich and poor, income inequality, wealth disparity, wealth and income differences or wealth gap) is the state of affairs in which assets, wealth, or income are distributed unequally among individuals in a group, among groups in a population, or among countries. The issue of economic inequality can implicate notions of equity, equality of outcome, equality of opportunity, and even life expectancy. Although the phrase uses the term income, the discussion often includes inequality in wealth or assets, which are different concepts.
Opinions differ on the importance of the concept of economic inequality and its effects. Some studies have emphasized inequality as a growing social problem. While some inequality promotes investment, too much inequality is destructive. Income inequality can hinder long term growth. Statistical studies comparing inequality to year-over-year economic growth have been inconclusive; however in 2011, researchers from the International Monetary Fund published work which indicated that income equality increased the duration of countries' economic growth spells more than free trade, low government corruption, foreign investment, or low foreign debt.