MultiplikatorAcceleratorModelle

MultiplikatorAcceleratorModelle, often translated as Multiplier-Accelerator Models, are a class of macroeconomic models that attempt to explain business cycle fluctuations through the interaction of the multiplier effect and the accelerator effect. The multiplier effect suggests that an initial change in autonomous spending, such as investment or government spending, leads to a larger change in aggregate income. The accelerator effect posits that the level of investment is related to the rate of change in output.

These models propose that the economy can be subject to cyclical instability due to the interplay of these two mechanisms. For instance, an increase in aggregate demand can lead to higher output. According to the accelerator principle, this rise in output will then stimulate a greater increase in investment, as firms seek to expand their capital stock to meet future demand. This surge in investment, in turn, acts as a further injection of demand, reinforcing the initial increase through the multiplier.

Conversely, a decline in aggregate demand can initiate a downward spiral. A fall in output might lead to a sharp reduction in investment due to the accelerator effect, as firms cut back on capital expenditures. This decrease in investment then reduces aggregate demand, causing further output declines and investment cuts.

Early versions of these models, developed by economists like R.F. Kahn and R.G.D. Allen, provided a theoretical framework for understanding endogenous business cycles. While these models have been influential in macroeconomic theory, they are often considered simplified representations of complex economic phenomena. Modern macroeconomic modeling incorporates more sophisticated treatments of investment, consumption, and other economic variables, but the fundamental insights of the multiplier and accelerator effects remain relevant. The models are useful for illustrating how dynamic interactions can generate cyclical behavior in an economy.