The Marginal Propensity to Imports [MPM] is defined as the amount of increase or decrease in the imports with each unit rise or fall in the disposable income. Thus, it can be defined as the change in imports divided by the change in income. It is a component of Keynesian economic theory and thus indicates the extent to which the imports are subjected to changes in the income or production. It can be understood that counties that have developed economies and have abundant availability of resources within their borders have lower MPM values.

Given,

                        Multiplier in the open economy = 4

            Marginal Propensity to save [MPS] = 0.6

Thus, Marginal Propensity to Consume [MPC] = 1-0.6 = 0.4

We have, Multiplier = 1/ [1-(MPC-MPM)] ; where MPMà Marginal Propensity to Import

Thus,

            4 = 1/ [1-(0.4-MPM)]

  Ie; 1-0.4+MPM = 0.25

Thus, 0.6 + MPM =0.25    

Thus, we have MPM = -0.35

Thus, from the above solution we can see that the Marginal Propensity to Imports is negative which means that an increase in the income generates a decline in the net imports