The correct option is Part of induced demand leaks out through imports.
Explanation
The investment multiplier quantifies the extent to which a change in autonomous spending (such as government expenditure or investment) increases the total aggregate income of an economy. The size of the multiplier depends inversely on the leakages from the circular flow of income.
Detailed Analysis
- Closed Economy Multiplier: In a closed economy, the primary leakage is savings (and taxes). The multiplier is calculated as:
Multiplier = 1 / (1 - MPC)
(Where MPC is the Marginal Propensity to Consume). - Open Economy Multiplier: In an open economy, an additional leakage exists in the form of imports. When domestic income rises, a portion of the induced consumption is spent on foreign goods and services. This is represented by the Marginal Propensity to Import (MPM).
- Mechanism of Leakage: Money spent on imports flows out of the domestic economy to foreign producers. Consequently, it does not generate further rounds of domestic income or consumption. This reduces the overall impact of the initial injection of spending.
- Formula Comparison: The open economy multiplier is:
Multiplier = 1 / (1 - MPC + MPM)
Since the denominator is larger (due to the addition of MPM), the value of the open economy multiplier is smaller than that of the closed economy multiplier.
Analysis of Incorrect Options:
- Fiscal expenditure has a weaker impact on output in open economies: While the multiplier effect is indeed smaller, stating that government spending is "less effective" is a consequence, not the fundamental economic explanation for the mathematical difference in multipliers.
- Higher taxation reduces the size of the multiplier: Tax rates are a matter of fiscal policy and vary by country; there is no economic rule stating taxes are generally higher in open economies.
- Capital inflows reduce domestic investment: Crowding out refers to the reduction in private investment due to higher interest rates caused by government borrowing. While relevant to fiscal policy effectiveness, it is not the primary reason for the difference in the standard multiplier formulas.
Key Takeaway:
The open economy multiplier is smaller because imports act as a leakage. A portion of increased income is spent on foreign goods (Marginal Propensity to Import), withdrawing purchasing power from the domestic circular flow.