Accelerator effect
（重定向自Accelerator Theory）
The accelerator effect in economics refers to a positive effect on private fixed investment of the growth of the market economy (measured e.g. by a change in Gross National Product). Rising GNP (an economic boom or prosperity) implies that businesses in general see rising profits, increased sales and cash flow, and greater use of existing capacity. This usually implies that profit expectations and business confidence rise, encouraging businesses to build more factories and other buildings and to install more machinery. (This expenditure is called fixed investment.) This may lead to further growth of the economy through the stimulation of consumer incomes and purchases, i.e., via the multiplier effect.