Fiscal, Monetary and Supply-Side Policy: Question 5

Worked solution

Part (a): Meaning of supply-side policy and the tools used

Supply-side policy refers to government measures aimed at increasing an economy’s productivity and its productive capacity, working by shifting the long-run aggregate supply (LRAS) curve to the right, rather than by shifting Aggregate Demand. In this scenario, Amberlyn’s government uses two supply-side tools: vocational training for workers, which raises the skills and productivity of the labour force, and investment in transport infrastructure (roads and ports), which improves the economy’s capital stock and the efficiency with which goods and inputs can be moved and distributed.

Part (b): Contrasting supply-side policy with a demand-side AD shift

If Amberlyn’s training and infrastructure programme succeeds in raising the economy’s productivity and productive capacity, its LRAS curve shifts to the right. This allows the economy to reach a higher equilibrium level of real output while the equilibrium price level remains stable, or even falls, because the underlying ability of the economy to produce output has genuinely increased, rather than more spending simply chasing the same fixed capacity.

By contrast, consider a purely demand-side policy, such as a rise in government spending (G), that shifts AD to the right but leaves LRAS unchanged. Holding LRAS fixed, this rightward AD shift also raises equilibrium real output, but it does so by moving further up a fixed aggregate supply curve, which puts upward pressure on the equilibrium price level too, and increasingly so the closer the economy already is to full employment and maximum capacity. Once the economy is at, or close to, full capacity, a demand-side stimulus with no accompanying rise in LRAS shows up mostly, or entirely, as a higher price level rather than extra real output.

The key contrast, then, is that a successful supply-side policy can raise real output without the same degree of inflationary pressure, because it expands what the economy is capable of producing, whereas a demand-side stimulus raises real output by pushing harder against an unchanged productive ceiling, which is more likely to show up as inflation.

Part (c): A limitation of supply-side policy

One significant limitation is the long time lag before supply-side measures actually raise productive capacity. Training workers to build new skills takes time to plan, deliver and for those skills to feed through into higher productivity on the job. Similarly, transport infrastructure such as new roads or ports must be planned, financed, built and commissioned before it can improve the efficiency of the economy. A process that can take several years. During this long implementation period, Amberlyn’s government still has to finance the spending (through taxation or borrowing), while the intended rise in productive capacity has not yet arrived. This makes supply-side policy far slower to affect the economy than fiscal or monetary policy, which can shift AD within a much shorter timeframe, and means supply-side policy is generally unsuitable as a quick response to a short-run economic problem.

Final answers

• (a) Supply-side policy raises productivity and productive capacity by shifting LRAS rightward; tools here are vocational training and transport infrastructure investment
• (b) Successful supply-side policy raises real output with little or no rise in the price level (LRAS shifts right); a pure demand-side AD shift with LRAS unchanged raises real output but also pushes up the price level, especially near full capacity
• (c) A key limitation is the long time lag before training and infrastructure investment actually raise productive capacity