Interaction of multiplier and accelerator is called?

Interaction of multiplier and accelerator is called?
The interaction of multiplier and accelerator which bring change in gross national income. The components of theory are warranted growth rate, consumption function, autonomous investment, induced investment and multiplier accelerator relationship. The economy is growing at warranted growth rate when saving and investment are equal. The economic fluctuations around the warranted growth rate are due to working of multiplier and accelerator. The consumption is considered the function of income of the previous period. When consumption lags behind income, the multiplier is treated as lagged relation. Autonomous investment is free from changes in output level so it is not concerned with growth of economy. Induced investment has a link with changes in output so it is related with economic growth rate. The accelerator is based on induced investment.
When investment level falls, the accelerator-multiplier works on the reverse direction. The price of contraction is slow as compared to expansion due to asymmetrical working accelerator. During expansion phase the limit to the expansion of real investment is set by production system capacity. In case of downturn the limit to disinvestment is set by depreciation. The businessman does not replace the worn-out machines. During slump multiplier work in reverse order and accelerator has limited role. Autonomous investment declines during slump but remains positive.
The cyclical process is repeated in this way.