The UK's Treasury committee has published a defence of the Office for Budget Responsibility, the independent fiscal watchdog created in 2010, against a growing chorus of critics who blame it for constraining government policy. The committee's verdict is blunt: the OBR is being scapegoated for fiscal constraints that chancellors created themselves. The attack surface is wide. From the left, academics like Prof Jo Michell and Dr Robert Calvert Jump argue the OBR has become a de facto veto on fiscal policy, with its headroom calculations acting as a binding constraint on spending decisions. Their charge is institutional creep — an unelected body determining the 'bounds of permissible fiscal policy.' From the right, the OBR has faced years of criticism for allegedly overestimating growth potential and underestimating the damage of austerity. Both critiques share a structural complaint: the five-year forecast window produces a single headroom number that drives enormous political consequences. Chair Dame Meg Hillier frames the issue precisely. The OBR's forecasts become disproportionately powerful when governments operate on razor-thin margins — and that thinness is a choice made by chancellors, not an imposition by forecasters. The committee explicitly rejected 'siren calls to fundamentally reform' the institution. The political incentive to blame the thermometer for the temperature is obvious; the committee is trying to short-circuit it. The committee's one substantive concession is worth noting. It recommends ministers consider instructing the OBR to produce a 10-year economic forecast alongside its existing five-year and 50-year outputs. The gap between a five-year horizon (which concentrates all political pressure into a single headroom number) and the 50-year fiscal sustainability report (which is too distant to constrain real decisions) is genuine. A 10-year forecast could force longer-term thinking about investment returns and structural trends without the speculative abstraction of half-century projections. The timing matters. The committee's review followed the December 2025 resignation of OBR chair Richard Hughes after a budget assessment leak. The institution is vulnerable. Hillier's call for the new chancellor to publicly and regularly defend the OBR's independence signals concern that political support cannot be assumed. The deeper structural question the committee touches but doesn't resolve is whether the fiscal rules themselves — not the OBR — are the binding constraint. The OBR does not set fiscal rules; it measures compliance with rules set by the chancellor. When the headroom number becomes the political story, the real question is whether the rules are well-designed, not whether the scorekeeper is too powerful. The Michell-Calvert Jump critique is aimed at the wrong target. Parliament debating the OBR's annual fiscal risks and sustainability report — the committee's other recommendation — would be a small but meaningful step toward treating long-term fiscal risk as a political question rather than a technocratic afterthought. Whether any government actually wants Parliament scrutinising 50-year fiscal fragility projections is another matter entirely.
