Causes of Deflation in Japan and Policies to Boost Growth and Inflation

Answer

Part (a) — How the factors contributed to deflation in Japan [10]

Deflation is a sustained fall in the general price level, so the inflation rate is negative for a prolonged period. It may be caused by a persistent fall in aggregate demand and/or a persistent rise in aggregate supply.

Poor global outlook — falling AD. Trade tensions and Brexit uncertainty make foreign consumers and firms cautious. Lower foreign demand cuts Japan’s export revenue, and weaker global investment lowers FDI into Japan, so net exports $(X-M)$ and investment $I$ — both components of AD — fall.

Shrinking and ageing population — falling AD. As workers retire, their income falls (pensions below prior earnings), lowering consumption $C$. A greying workforce is perceived as less productive, deterring FDI and lowering $I$; and retirees drawing down savings reduce the supply of loanable funds, raising interest rates and discouraging investment further.

Because these demographic trends are unlikely to reverse, households and firms expect further falls in demand and prices, holding back spending and investment — a self-reinforcing leftward drift of AD that entrenches deflation.

Falling crude oil prices — rising AS. Crude oil is an essential input. Cheaper oil lowers firms’ costs of production, raising short-run aggregate supply (the AS curve shifts down). A persistent fall in oil prices produces a sustained rise in AS and a falling price level — supply-side deflation, though this variety is accompanied by rising output and is therefore more benign.

Part (b) — Relative effectiveness of policies to boost growth and inflation [15]

Demand-side deflation is the real concern, because it brings negative actual growth and rising demand-deficient unemployment; supply-side deflation from cheap oil is benign. The objective is therefore to raise AD (and address the demographic drag on AS) to achieve actual growth and lift the inflation rate toward target.

Expansionary monetary policy — and its limits. The Bank of Japan’s bond purchases lower interest rates, cutting the cost of borrowing and the return to saving, encouraging $C$ and $I$; lower rates may also cause yen depreciation, raising $(X-M)$ if the Marshall–Lerner condition holds. With spare capacity, the rise in AD is multiplied, raising real output and the price level.

The limitation is decisive here: amid a poor outlook and entrenched demographic decline, consumers and firms are interest-insensitive — pessimism leads households to save and firms not to invest even at near-zero rates (a liquidity-trap problem), so the monetary policy transmission is weak. This is exactly why “massive monetary stimulus” has left the 2% target elusive.

Expansionary fiscal policy — and its limits. Higher government spending and tax cuts raise AD directly, bypassing the broken interest channel, and government spending on infrastructure also raises productive capacity. But Japan already carries very high public debt, so the fiscal space is constrained, and time lags blunt timeliness.

Supply-side policy — addressing the root demographic cause. Measures to raise labour productivity — automation, retraining, raising participation among women and older workers — offset the shrinking workforce, raising potential output and, by lifting incomes and confidence, supporting demand. Its weakness is that it is slow and, by raising AS, could in the short run lower the price level further — counterproductive to the immediate goal of raising inflation.

Judgement. No single policy is sufficient. Monetary policy, the BoJ’s chosen lever, is the least effective in Japan’s circumstances because pessimism and demographics render spending interest-insensitive. Fiscal policy is more effective at directly raising AD and the inflation rate, but is constrained by Japan’s debt. Supply-side policy is essential for the long-run root cause — the demographic drag — but works slowly and can deepen deflation in the short run. The most effective approach is therefore a coordinated mix: fiscal expansion to raise AD and inflation now (since monetary policy alone cannot), paired with supply-side measures to lift productivity and confidence over time — with monetary easing playing a supporting rather than leading role. The relative effectiveness ultimately hinges on restoring the confidence that Japan’s demographics and global outlook have eroded, which is the binding constraint on every demand-side instrument.