A variable which can take any value, and is not confined to particular values, such as integers. The techniques of calculus apply only to continuous variables. Many economic variables, including prices and incomes, are measured in money terms: as money comes in discrete units, it is not a continuous variable. Economic models frequently treat monetary variables as continuous: this is very convenient, and as the units are so small it is thought to introduce negligible errors.

• 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
• incumbent firm
• indefinite integral
• independence, central bank
• independent risks
• independent taxation of spouses
• index
• indexation
• Index, Laspeyres
• index-linked
• index number
• Index of Industrial Production