Correct Option
The correct option is 1 and 3 only.
Explanation
In a simple two-sector economy (consisting of households and firms with no government or foreign sector), macroeconomic equilibrium is determined where Aggregate Demand (AD) equals Aggregate Supply (AS). This state ensures that the total output produced is exactly consumed or invested as planned, with no tendency for income or output to change.
Statement-wise Analysis
- Statement 1 is Correct: The equilibrium condition can be derived from the circular flow of income, where leakages must equal injections. In a two-sector model, Savings represent a leakage and Investment represents an injection. Equilibrium is established when Planned Savings equal Planned Investment ($S = I$). If they are unequal, the economy adjusts output until equality is restored.
- Statement 2 is Incorrect: Equilibrium is strictly defined as the point where Aggregate Demand equals Aggregate Supply ($AD = AS$). If Aggregate Demand is greater than Aggregate Supply ($AD > AS$), there is excess demand in the economy. This leads to the depletion of inventories and pressure on firms to increase output, representing a state of disequilibrium rather than stability.
- Statement 3 is Correct: Unintended inventory investment refers to the accumulation or depletion of stocks due to unexpected sales figures. At equilibrium, firms sell exactly what they planned to sell ($AD = AS$). Therefore, actual investment equals planned investment, and unintended inventory investment is zero.
Key Takeaway
Key Takeaway: Macroeconomic equilibrium in a two-sector economy requires that Aggregate Demand equals Aggregate Supply ($AD = AS$), Planned Savings equal Planned Investment ($S = I$), and there are no unplanned changes in inventory stocks.