What is the range

An investment multiplier determines the financial impact of a public or private project on the economy.

Investment increases productive capacity that raises the level of output, employment and income. When investment increases by a certain amount, aggregate income increases by a multiple of that investment.This multiple is called investment multiplier.

MPC is the increase in the amount of consumption from the increase in the income of the person.

Multiplier=1/(1-MPC)

If MPC is high the value of multiplier will also be high.

Marginal propensity to save (MPS) refers to the proportion of any extra income that is saved by consumers.

MPS = 1-MPC

So if MPS increases then MPC decreases, and we know when MPC decreases then multiplier also decreases.