Immediate labor supply boost drives short-run aggregate supply growth

Steps:

• Define supply-side measures as policies increasing productive capacity, like labor or capital enhancements.
• Focus on short-run effects: policies with quick implementation and impact on factors of production.
• Evaluate each option for speed of increasing aggregate supply (AS) curve shift.
• Select the one directly expanding labor force without delays.

Why A is correct:

• Easing immigration controls rapidly increases labor supply, shifting AS rightward per the production function Y = f(L, K, Tech), where L (labor) rises immediately.

Why the others are wrong:

• B: Primary education improves skills over years, yielding long-run AS growth.
• C: R&D fosters innovation but requires time for implementation and results.
• D: Privatization may enhance efficiency yet often involves transitional disruptions, not instant AS expansion.

Final answer: A