The unemployment that would exist because, as people change jobs because some sectors of the economy grow and others contract, it is not practicable to dovetail precisely leaving old jobs and starting new ones. At times of fairly full employment, frictional unemployment may form an appreciable fraction of total unemployment. Under conditions of high unemployment its contribution is probably negligible, except in sectors with localized labour shortages.

• incidence of taxation
• income
• income approach to GDP
• income change, compensating
• income distribution
• income effect
• income elasticity of demand
• income expansion path
• income from employment
• income from self-employment
• income inequality
• income method
• income per capita
• income redistribution
• incomes and prices policy
• incomes policy
• income support
• income tax
• income velocity of circulation
• incomplete information
• incomplete markets
• increase in the book value of stocks and work in progress
• increasing function
• increasing returns to scale
• incremental capital-output ratio