Monetary policy occupies a peculiar position in modern economics: ubiquitous in crisis management, yet fundamentally constrained by forces beyond any central bank's control. A recent address by Lesetja Kganyago, Governor of the South African Reserve Bank, crystallizes this uncomfortable truth. When inflation results from supply disruptions—broken supply chains, commodity shocks, climate-driven agricultural failures—raising interest rates becomes an act of economic theater. The central banker tightens policy. The economy slows. Unemployment rises. But prices, driven by scarcity rather than demand, may barely budge.
This distinction between demand-pull and cost-push inflation has haunted policymakers since the stagflation of the 1970s, yet it remains underappreciated in current debates. The prevailing orthodoxy holds that inflation is, ultimately, a monetary phenomenon—the result of too much money chasing too few goods. By this logic, central banks armed with interest-rate tools should be able to engineer price stability. But Kganyago's analysis, delivered at Rhodes University in Grahamstown, points toward a more textured reality: one where the transmission mechanisms of monetary policy break down when the source of price pressure lies upstream in production and distribution networks rather than in aggregate demand.
South Africa exemplifies this predicament. The nation confronts recurring electricity shortages, logistics bottlenecks, and commodity-price volatility—all exogenous to the central bank's balance sheet. When a drought reduces maize yields or when load shedding (rolling blackouts) disrupts manufacturing, the SARB Governor faces a trilemma. Tightening monetary policy to anchor inflation expectations may succeed in dampening demand, but it does so by cooling economic activity and raising joblessness. In a nation grappling with structural unemployment above 30 percent, this trade-off carries acute social costs. Conversely, accommodating supply shocks through looser policy risks allowing temporary price spikes to become embedded in wage and price-setting behavior, ultimately requiring more aggressive tightening later.
The challenge deepens when inflation targets are treated as mechanical constraints. Many central banks, including the SARB, operate within formal inflation-targeting frameworks—typically aiming for a midpoint of 3 to 5 percent in South Africa's case. These targets serve an important anchoring function, signaling commitment to price stability and preventing inflation expectations from becoming unmoored. Yet when supply shocks push inflation above target for extended periods, public and political pressure mounts for the central bank to "do something." The danger lies in mistaking a central bank's legitimacy for its power. A governor cannot print semiconductors. Interest rates cannot unclog ports.
This realization should reshape how economists and policymakers conceptualize the central bank's role in a supply-constrained world. The inflation problem of the 2020s—driven by pandemic-era production failures, energy transitions, geopolitical fragmentation, and climate volatility—is fundamentally different from the demand-driven inflation that monetary-policy frameworks were engineered to manage. Higher rates may eventually break demand sufficiently to lower prices, but at tremendous cost to employment and growth. The alternative—accepting temporarily elevated inflation while structural bottlenecks resolve—requires far greater intellectual humility from central bankers and far greater forbearance from the public.
For emerging markets like South Africa, the stakes are especially high. Capital markets punish inflation breaches with capital flight and currency depreciation, which in turn raises import costs and feeds back into domestic prices. A developing economy cannot simply absorb higher inflation without triggering a currency crisis. Yet the flip side—aggressive rate hikes to maintain credibility with foreign investors—can throttle growth precisely when structural transformation and job creation are most urgent. Kganyago's framing acknowledges this bind without offering easy escape: monetary policy cannot conjure supply. It can only manage the demand side of the inflation equation, and even that management carries collateral damage.
The broader implication extends to the architecture of economic governance. If monetary policy alone proves insufficient to navigate supply-driven inflation, then fiscal policy, industrial policy, and supply-side reforms must carry greater weight. Governments must invest in productive capacity, infrastructure, and energy security. Competition authorities must prevent artificial supply constraints from emerging in critical sectors. Trade policy should aim to deepen integration and resilience in supply networks. The central bank, in this view, becomes one instrument among many—powerful but circumscribed, and most effective when working in concert with complementary policies rather than in isolation.
What emerges from Kganyago's analysis is neither pessimism nor abdication of responsibility. Rather, it is a call for clearer expectations about what monetary policy can and cannot achieve when the inflation problem is structural rather than cyclical. Central bankers should continue to anchor price expectations and pursue price stability as a public good. But they should do so with full transparency about the limits of their toolkit and with explicit acknowledgment that defeating inflation rooted in supply constraints requires action far beyond the remit of any single central bank. The 3 percent inflation target remains a worthy objective—but achieving it demands more than higher interest rates.
Written by the editorial team — independent journalism powered by Codego Press.
