When the Same Inflation Number Means Different Things
The Federal Reserve's alternative scenarios become genuinely informative when they are read as causal maps rather than as extra numbers beside a forecast. This chapter connects the established ideas about baselines, model mechanisms, and uncertainty into one judgment: identify what changed, follow how it travelled through the economy, compare output and inflation with the baseline, and then ask what policy dilemma followed. That method also explains why a wide range of scenarios is not the same thing as a probability distribution.
Read the shock before reading the number
The Federal Reserve study groups its scenarios by the primary risk they address. The categories are aggregate demand, aggregate supply, external or global risks, financial markets and stability, fiscal and regulatory risks, and public expectations. They are not six sealed compartments. A financial disturbance can reduce demand, a foreign shock can affect supply, and fiscal policy can alter expectations. The classification records the main focus of a scenario so that the historical set can be compared; it does not claim that an economic event has only one channel.
The distinction between demand and supply provides the clearest starting point. A demand scenario changes overall spending—perhaps through consumption, investment, or broader economic activity. If households save less of their income than expected, spending is stronger. In the type of model exercise discussed by the BIS, that positive demand shock raises inflation and GDP together. The economy is hotter, and the policy problem is how to prevent excess demand from pushing inflation away from its objective without unnecessarily suppressing output.
A supply scenario changes the economy's capacity to produce, or the conditions under which production takes place. Slower productivity is the clean example. It can raise firms' costs and prices while reducing the amount the economy can produce. Inflation rises, but GDP falls relative to the baseline. The central bank now faces a more difficult trade-off: restraining inflation may further weaken activity, while supporting activity may allow the supply-driven price pressure to persist.
The two scenarios can therefore begin with the same headline concern—higher inflation—and still imply different choices. The number tells us where inflation ended up relative to the baseline. The risk family tells us why. Without that causal identity, a reader may treat every inflation increase as evidence for the same policy response.
The other Federal Reserve categories widen the map without making it unmanageably abstract. External or global risks include international conditions and shocks that reach the domestic economy through trade, exchange rates, foreign demand, or imported prices. The study finds a wide spread of output and inflation outcomes for these scenarios, which is consistent with the fact that an external development can push different parts of the domestic economy in different directions.
Financial-market and stability scenarios focus on asset prices, risk premiums, credit conditions, sentiment, or systemic stress. In the historical classification, they primarily affected real GDP and had less dispersion than aggregate-demand scenarios. That pattern does not mean financial risks are minor. It means their most visible modeled effect was often on activity: borrowing becomes harder, wealth changes, or confidence weakens, and spending responds.
Fiscal and regulatory scenarios concern nonmonetary government policy and its economic effects. The Federal Reserve study finds that these appeared less often and were concentrated around major fiscal debates.