The multiplier, or the change in equilibrium GDP that will occur per any change in spending, can be determined by calculating the fraction of any change in income that survives all of the leakages and goes on to start the next round of spending. That is, the multiplier depends upon the fraction of any change in income that becomes...

the change in exports

the change in savings

the change in imports

the change in domestic consumer spending

the change in disposable income

the change in business investment spending