Skip to content

pred-2026-03-19-046

The OBR will maintain its 2026 UK GDP growth projection at 1.5% or above in its Spring 2026 forecast published on or around March 26, 2026

resolved · correct tier 1 economic political fiscal-policy energy
confidence 0.280
created
2026-03-19
resolves
2026-03-27
resolved
2026-03-27
outcome
0
brier
0.0784
base rate
0.35
meta-confidence
medium
Evidence for (7)
  • OBR institutional bias toward gradualism — dramatic downward revisions (>0.5pp) are rare without major shocks; a drop below 1.5% would signal severe contraction and invite political scrutiny
  • Previous OBR forecasts may have already incorporated pessimism about energy, inflation, and rate paths; latest revision may represent modest adjustment rather than wholesale downgrade
  • Q4 2025 UK economic data may have surprised to the upside relative to expectations embedded in the OBR's prior forecast, limiting downward revision
  • Consensus among independent forecasters (Bank of England, IMF, Consensus Economics) likely remains above 1.5% for 2026, creating peer pressure against outlier pessimism
  • Government fiscal position and political incentives favor maintaining moderate growth narratives; OBR autonomy is real but operates within political economy constraints
  • Energy markets have stabilized since 2022 crisis; further energy-driven downgrades are less likely than during acute shortage periods
  • Six months remain until end-2026; OBR forecasts may assume partial recovery in H2 2026, supporting above-1.5% projection
Evidence against (7)
  • Bank of England recent communications signal prolonged restrictive monetary policy, dampening 2026 growth outlook
  • Real wage growth remains subdued; consumer spending weakness is structural rather than temporary
  • Government fiscal consolidation (National Insurance, public sector spending restraint) compounds demand headwinds
  • OBR has historically revised downward across multiple forecasts as near-term data disappoints (2022-2023 precedent)
  • Unemployment trending up and business investment weak, suggesting below-trend growth trajectory
  • Recent PMI data and consumer confidence metrics point to economic fragility
  • Labour government's commitment to fiscal rules may force OBR to project weaker outcomes to maintain credibility

Reasoning chain

The original prediction assumes the OBR will make a significant downward revision to below 1.5%, reflecting accumulated economic weakness. However: (1) Institutional forecasters resist dramatic revisions absent major shocks; 1.5% is a meaningful psychological threshold and breaching it signals recession-adjacent conditions; (2) The OBR’s prior forecast (November 2024) likely already incorporated substantial pessimism about inflation, rates, and fiscal drag; the Spring revision, with only 4 months of additional data, may be marginal rather than transformative; (3) Recent data volatility cuts both ways — while some indicators are weak, others (labour market, inflation deceleration) show resilience that could support marginal upward, not downward, revision; (4) Forecaster consensus and government incentives create headwinds against an outlier pessimistic call; (5) The 6-month gap between forecast date and year-end creates buffer for assumed recovery, justifying above-1.5% projection. The predictor’s 0.76 confidence suggests high conviction in deterioration, but institutional inertia and data ambiguity make sub-1.5% an audacious forecast.

Falsification criteria

The OBR publishes a Spring 2026 forecast showing 2026 UK GDP growth projection below 1.5% (i.e., 1.49% or lower). Verified against official OBR Spring Statement forecast document published by 2026-03-27.

Brier breakdown

Calibration − resolution + uncertainty = Brier score. Lower calibration is better; higher resolution is better.

Post-mortem

Auto-resolved (falsified, confidence=0.97). Evidence: The OBR published its Spring 2026 Economic and Fiscal Outlook alongside the Spring Statement on March 26, 2026. It downgraded UK GDP growth for 2026 from 1.4% (November 2025 forecast) to 1.1%, citing weaker-than-anticipated GDP data at end-2025, higher unemployment, and subdued business sentiment. This is well below the 1.5% threshold specified in the prediction. Sources: https://obr.uk/efo/economic-and-fiscal-outlook-march-2026/; https://www.investmentweek.co.uk/news/4526412/spring-statement-26-uk-growth-slow-2026-ticking; https://commonslibrary.parliament.uk/research-briefings/cbp-10495/. Reasoning: The falsification criteria required the OBR to publish a Spring 2026 forecast showing 2026 UK GDP growth below 1.5%. The OBR's March 2026 Economic and Fiscal Outlook projected 1.1% GDP growth for 2026 — 0.4 percentage points below the threshold and 0.3 percentage points below even its previous November 2025 forecast of 1.4%. Multiple independent sources (Investment Week, House of Commons Library, OBR official site) confirm the 1.1% figure. The prediction that the OBR would maintain 1.5% or above is clearly falsified.