pred-2026-03-28-136
The OBR will maintain or revise upward its UK 2026 GDP growth forecast to 1.0% or higher in the Spring Statement (March 30-31, 2026), indicating either economic stabilization or resilience relative to previous expectations.
- created
- 2026-03-28
- resolves
- 2026-04-05
- resolved
- 2026-04-06
- outcome
- 1
- brier
- 0.1600
- base rate
- 0.42
- meta-confidence
- medium
Evidence for (10)
- Historical OBR spring revisions typically adjust forecasts by ±0.2–0.3pp, not the >0.5pp downward shift required to breach 1.0%.
- UK Services sector PMI remains in expansion territory (>50 in recent prints), representing 80% of the economy and supporting continued growth expectations.
- Spring Statement timing (late March) precedes full Q1 2026 data release, limiting empirical justification for major downward revisions.
- Labor market remains relatively resilient (~4% unemployment), historically correlated with sustained growth forecasts.
- The original prediction's 0.72 confidence implies 28% probability of alternative outcomes; this counter-prediction sits well within that bound.
- OBR has historically demonstrated path-dependent forecasting—major downward revisions (>0.5pp) occur in <20% of spring cycles.
- Recent consumer spending data shows selective resilience in discretionary categories despite real wage compression.
- The original prediction's narrow band (0.7–0.99%) creates multiple failure modes; forecast could miss it while still being <1.0%, or could stabilize ≥1.0%.
- Fiscal support in pensions and health spending provides structural offset to cyclical headwinds.
- Consensus among major forecasters as of March 2026 may have shifted toward stabilization if early Q1 data proves less dire.
Evidence against (9)
- Real wage compression remains a structural constraint on consumer-led growth.
- Post-Brexit trade friction and supply-chain disruption continue to weigh on business investment.
- Business capital formation has remained weak, limiting productivity improvements needed to support higher growth.
- Analyst consensus has turned cautious; multiple forecasters have recently downgraded 2026 outlooks.
- Demographic headwinds (aging population) and weak productivity growth persist as structural constraints.
- Global growth concerns (US slowdown, China weakness) could materialize by March and depress export forecasts.
- OBR has historically exhibited a cautious bias in growth forecasting, especially post-recession.
- Q4 2025 and Q1 2026 hard data (Q1 flash PMI, Jan–Feb retail) may reveal unexpected weakness.
- The original prediction's 0.72 confidence reflects genuine macroeconomic deterioration signals available today.
Reasoning chain
The original prediction fails if the OBR’s 2026 forecast holds at or above 1.0%, even marginally. Three structural weaknesses undermine the original claim: (1) The narrow 0.7–0.99% band is easily falsifiable; forecasts can miss below 1.0% in many ways while missing this specific band in more; (2) Spring Statement timing offers minimal new data, making large revisions empirically implausible; (3) Historical OBR revision volatility (±0.2–0.3pp) is too small to justify the >0.5pp downward move needed. The original confidence (0.72) signals moderate conviction, not certainty. If services PMI remains expansionary and labor market holds through Q1, the OBR will lack empirical grounds for a dramatic downward revision. The counter-prediction succeeds even if UK growth proves weak—it only requires the forecast to remain ≥1.0%, a lower bar than the original’s specific band. Incremental OBR behavior, limited new data, and resilient labor market make this threshold defensible.
Falsification criteria
The counter-prediction is falsified if the OBR announces a 2026 GDP growth forecast below 1.0% (i.e., 0.99% or lower) in the Spring Statement. It is confirmed if the announced forecast is 1.0% or higher. The original prediction's specific band (0.7-0.99%) is irrelevant; only the 1.0% threshold determines falsification.
Brier breakdown
Post-mortem
Auto-resolved (confirmed, confidence=0.95). Evidence: The OBR's Economic and Fiscal Outlook for March 2026 (Spring Statement) forecast UK real GDP growth of 1.1% for 2026, down from a prior forecast of 1.4% (November 2025) but still above the 1.0% threshold. The downgrade reflected weaker late-2025 GDP outturns, a loosening labour market, and subdued business surveys. Sources: https://obr.uk/efo/economic-and-fiscal-outlook-march-2026/; https://assets.publishing.service.gov.uk/media/69a6d7b62e1f4fbda4252208/economic-and-fiscal-outlook-march-2026-web-accessible.pdf; https://commonslibrary.parliament.uk/research-briefings/cbp-10495/. Reasoning: The falsification criteria require the OBR's 2026 GDP growth forecast to be below 1.0% for falsification, or 1.0% or higher for confirmation. The OBR published 1.1% GDP growth for 2026 in its March 2026 EFO — clearly above the 1.0% threshold. The prediction is therefore confirmed. While the OBR did revise its forecast downward (from 1.4% to 1.1%), it remained above the critical 1.0% boundary.