withdraws

• Modelling imports-  income can either be spent or saved 

  S= -A + sY

  -A stands for the autonomous dissaving

  Y is the level of income 

   s is the marginal propensity to save  s = ΔS/ΔY, s = 1 – c
• Net taxes- as national income increases the amount paid in tax will also increase, the marginal tax propensity is the proportion of an increase in national income paid in taxes, depending on tax rates 
• Imports- the higher national income the higher imports, the marginal propensity to import is proportion of a rise of national income that goes on imports, only count expenditure which goes abroad