Multiplier effect is a macroeconomic effect, a means of macroeconomic regulation and control, and refers to the chain reaction degree of economic aggregate changes caused by the increase or decrease of a certain variable in economic activities. The fiscal policy multiplier is to study the influence of fiscal revenue and expenditure changes on the national economy, including fiscal expenditure multiplier, tax multiplier and balanced budget multiplier.

Its concept in regional economic development: it refers to demonstrating, organizing and driving the surrounding areas through industrial association and regional association. Through circulation and causal accumulation, this effect is constantly strengthened, amplified and expanded. It refers to the degree of chain reaction caused by the increase or decrease of a variable in economic activities. In economics, multiplier effect is more completely expenditure/income multiplier effect, which is a concept of macroeconomics. This means that changes in expenditure lead to disproportionate changes in total economic demand. It is a variable that causes the increase of the final quantity in the form of multiplier acceleration. It is a factor to be considered in formulating macro policies.