Since the sum of MPC and MPS is unity (MPC+MPS=1) ,any increase in Marginal Propensity to Save (MPS) would directly lead to a decrease in Marginal Propensity to Consume(MPC). This means that lesser proportion of additional income is going to consumption, which is a vital factor of Aggregate Demand/ Expenditure.. This may further lead to a fall in equilibrium level of income in the economy. Due to this fact, Economist are generally concerned about the rising MPS in an economy.
