To let it rise from zero this year to 55 percent next year seems absurd on fairness grounds, but it would also have severe supply-side effects.

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But these big supply-side effects are implausible at best.

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Price controls, even if laboriously tweaked, inevitably produce inefficiencies, reduce supply and cause bad side-effects.

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The fundamental point is that, in the presence of inelastic supply curves, demand-side subsidies face a headwind of adverse price effects, while direct public provision gets a tail wind of favorable price effects.

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If he's wrong - if there is, in fact, a faster growth path available, which would not undermine market confidence, then the government's strategy could be making the supply side problem a self-fulfilling prophesy, by condemning us to unnecessarily slow growth which could have permanent effects on Britain's potential output.

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