The First Months: Why Prices and Activity Rise Together
A fiscal-risk shock does not necessarily begin with a recession. The specific question here is why a sovereign repricing can lift the consumer price level and industrial production at the same time, and how that early combination should be interpreted. The answer is a timing pattern: a temporary demand impulse and higher inflation expectations arrive before the full effect of more expensive sovereign finance is visible, while currency depreciation can keep adding price pressure after the first impulse fades.
A temporary demand impulse can lift prices and production together
When investors revise the government's fiscal path, the immediate economic response need not be a clean subtraction from demand. The fiscal event may include new transfers, public purchases, tax relief, or expectations that support will continue. Even if the market doubts how those commitments will eventually be financed, the spending itself can reach households and firms before the financing constraint has worked through contracts and balance sheets. Production can rise for a time because there is more demand to meet.
Prices can rise alongside it for two related reasons. First, the additional demand meets available capacity and gives firms an incentive to raise prices. Second, the fiscal-risk repricing can change beliefs about future inflation. If households, firms, and investors expect the government to tolerate or generate more inflation to ease its obligations, that expectation affects current wage, price, and contract decisions. Inflation expectations are not the same as realized inflation, but they can help turn a temporary fiscal impulse into a broader price response.
The exchange rate adds a third channel in an open economy. A loss of confidence in sovereign debt can reduce demand for the country's assets and put downward pressure on its currency. A weaker currency raises the domestic-currency price of imported energy, food, intermediate inputs, and finished goods. The pass-through is neither immediate nor complete for every product, but it gives the price level another reason to keep rising after the initial demand impulse has begun to fade. In this way, the fiscal-risk episode can produce an inflationary burst without requiring the economy to remain strong throughout the episode.
The baseline BIS estimates fit that sequence. They are normalized to a one-percentage-point increase in the five-year government yield caused by a fiscal-risk shock. Consumer prices—the price level measured by headline CPI—rise immediately, with the point estimate about 1–1.5 percent higher over the ten months after the shock before fading. One-year-ahead inflation expectations rise by roughly 0.5 percentage points, with the increase statistically significant for about five months. Industrial production rises during the first four months, consistent with a temporary demand effect, and turns negative afterward.
Those figures should be read as an impulse path, not as a claim that a single budget announcement mechanically raises all prices by a fixed amount. The one-percentage-point denominator is a market response: it is the component of the five-year sovereign yield attributed to fiscal risk. The study does not convert a one-percentage-point deficit increase into a forecast for CPI. Nor does it say that the price level rises because investors have made a mistake. The market's repricing is itself part of the mechanism: it changes financing expectations, the currency, and the way private actors assess future policy.
The early activity increase is equally easy to misread. A few months of higher industrial production can make a fiscal measure look unambiguously successful if the observation window ends there. But the study follows the path beyond the first quarter. Production's initial increase is not evidence that the later cost of sovereign risk will be absent. It shows that demand can respond faster than the financial constraints that eventually determine whether firms continue to invest and households continue to borrow. The first phase is therefore a real response, but it is not the whole response.
The estimates also use different measures of prices and expectations, and keeping them separate matters. A consumer-price level estimated to be 1–1.5 percent higher over ten months is not the same as saying that monthly inflation stayed at 1–1.5 percent. It describes the cumulative distance between the post-shock price path and the path that would otherwise have prevailed. The roughly 0.5-percentage-point increase in one-year-ahead inflation expectations is a forecast measure, not another reading of the current CPI. The two measures together say that prices move up and that people expect some of the pressure to persist, but they do not imply a permanently higher inflation rate.
The timing of production reinforces this distinction. A fiscal measure can reach current demand through income or public purchases before it changes the financing choices that determine future activity. A firm may receive an order today while still facing a more expensive capital decision later; a household may spend a transfer before reassessing borrowing at a higher rate. The BIS result does not require every firm or household to respond in the same way. It identifies an average path in which the early demand response is visible first and the negative real-activity response takes longer to emerge.
Currency depreciation gives the price level a second clock. Imported goods and inputs are repriced as contracts renew, inventories turn over, and sellers pass through part of the exchange-rate change. The pass-through can differ by product and economy, so the evidence does not support a universal timetable. It does support the direction of the mechanism: once a fiscal-risk shock weakens the currency, domestic buyers need more local currency for some of the same foreign goods. That pressure can keep the price level rising even as the initial fiscal demand effect loses force.
Expectations can make the two clocks interact. If firms believe that future inflation will be higher, they may be less willing to treat a temporary cost increase as temporary; if households expect prices to keep rising, they may change the timing of purchases and wage demands. These reactions are not separately identified as individual behavioral effects in the BIS estimates. They are part of the paper's interpretation of why inflation expectations rise on impact and why price pressure can outlast the first production response. The useful conclusion is conditional, not psychological: expectations matter because they alter the path that current prices and policy rates must eventually follow.
The sequence has an important asymmetry. Demand support can be front-loaded: a transfer or spending decision affects current income quickly. Exchange-rate pass-through and expectations can keep prices moving for several months. The effect of higher financing costs, by contrast, often becomes visible only as borrowing conditions adjust and future spending or investment is reassessed. This difference in speed is enough to make prices and output rise together at first and diverge later.
Inflation changes the debt arithmetic—but not necessarily for the better
It is tempting to stop the analysis at a familiar piece of arithmetic. If the government has issued fixed nominal debt, a higher price level reduces the real value of the payments it must make. Nominal GDP also rises when prices rise, which can make the debt-to-GDP ratio look smaller. This is a genuine mechanical effect, and it is one reason inflation can appear to offer a government an escape from a heavy debt burden.
But the government budget is not a single fixed nominal liability. Some expenditures are indexed to prices or respond automatically when real activity weakens. Revenues may respond more slowly, especially when higher prices reduce real household purchasing power or compress the real profits of firms. If expenditures adjust faster than revenues, the primary balance—the fiscal balance before interest payments—can deteriorate. The inflation that reduced the real value of old debt may at the same time reduce the fiscal room available to service or refinance it.
The market also prices the consequences of the policy response. If inflation expectations rise, tighter monetary policy can raise sovereign borrowing costs. As higher market rates apply to new and refinanced obligations, the initial relief from eroding old nominal liabilities can be replaced by higher interest costs. Even without an explicit default, investors can interpret this combination—indexed spending, weak revenues, rising rates, and uncertain future policy—as evidence of greater sovereign risk.
The IMF's Fiscal Monitor adds a useful caution by separating the mechanical effect of inflation from the economic quality of the inflation. Supply-driven inflation can lower the debt ratio in nominal terms while squeezing real household incomes and corporate profits. Tighter monetary policy can raise sovereign borrowing costs, and pressure to support households during a price shock can add to the fiscal strain. The arithmetic looks favorable in one column and damaging in the next.
The balance-sheet effect depends on what changes automatically and what does not. Fixed nominal payments may become easier to meet in real terms, but price-linked spending can rise with the same shock. Revenue may grow in nominal terms without keeping pace with spending or with the real cost of public services. The relevant question is therefore not simply whether inflation raises nominal GDP, but whether the government's primary balance and financing conditions improve after accounting for these responses.
A useful way to read the sequence is to separate three ledgers. The first is the stock of old nominal debt, whose real burden may fall. The second is the flow budget, where indexed outlays, automatic stabilizers, and slower revenue adjustment can worsen the primary balance. The third is the market ledger, where higher inflation expectations and tighter policy raise the compensation investors require. A favorable movement in the first ledger can be outweighed by adverse movements in the other two. This is why an apparent reduction in the debt ratio does not by itself restore fiscal space.
This is also why the source of the early inflation matters. The BIS paper's fiscal-risk shocks can include events associated with temporary fiscal expansions, but the authors explicitly note that the measure aggregates different kinds of fiscal-risk news. A fiscal package that creates near-term demand is not identical to adverse information about future repayment capacity that has little immediate stimulus. Both can raise sovereign risk, yet their early effects on production and prices need not match. The pooled impulse response describes the average market-repricing path in the study's sample, not a universal response to every fiscal announcement.
The distinction protects against two opposite errors. One error is to say that inflation is harmless because it lowers the real value of existing debt. That ignores indexed outlays, weaker real incomes, higher risk premia, and the cost of refinancing. The other is to say that every early price increase proves fiscal policy has already destroyed productive capacity. The estimated path is more specific: consumer prices and expectations rise early, activity receives a temporary lift, and the eventual negative production response takes longer to become visible.
The timing also changes how evidence should be read. A headline about stronger output immediately after a fiscal announcement is not a contradiction of a later growth drag; it may be the first stage of the same episode. Conversely, an early rise in prices is not sufficient evidence that the fiscal-risk mechanism is operating, because supply shocks and ordinary monetary news can produce inflation too. The market identification described previously is what makes it possible to connect the measured sovereign repricing to this particular sequence.
Reading the first phase without mistaking it for the destination
The first months reveal the interaction between three things: current demand, beliefs about future inflation, and the currency in which the economy buys imported goods. Together they explain why the initial response can look superficially expansionary. But the response is already carrying a cost. The BIS estimates show long-term government yields rising about 0.5–1 percentage point in the first year, and the trade-weighted nominal exchange rate depreciating significantly after about six months. The price and financing sides of the episode are therefore moving in opposite directions before the full output drag appears.
The most defensible reading is neither “fiscal support works” nor “markets instantly punish all spending.” It is that markets can allow a short-lived demand gain while repricing the government's future constraints. The gain belongs to the near term; the constraints accumulate over a longer horizon. The strength of the price response depends on expectations and currency exposure, while the later real cost depends on how the sovereign repricing reaches borrowing and investment. Country conditions and monetary policy can make either part larger or more persistent.
That gives the early phase a precise place in the overall explanation. It is the first turn of a fiscal-risk shock, not a self-contained verdict on fiscal policy. The reader can now hold the initial chain together: unexpected fiscal news changes sovereign pricing; expectations and currency weakness lift prices; temporary demand supports activity; and the price-level arithmetic does not guarantee better fiscal sustainability. The next task is to consolidate those links and their qualifications before following the repricing into the financial conditions that make the growth drag persistent.