Explain the impact of a 200 million pound increase in government expenditure on national income in the following three cases. In your calculations use the following data where appropriate; the marginal propensity to consume is 0.6; the income tax rate is 50 per cent of all income and the marginal propensity to import is 0.2.

• a closed economy multiplier with no income taxes
• a closed economy multiplier with government income taxes.
• an open economy multiplier with no government taxes.