The IFS raises a far better question on Labour's renationalisation plans | Nils Pratley

Key issue is how well assets such as railways and energy would run under public ownership, not the cost

The Institute for Fiscal Studies is asking the right question about Labour's nationalisation plans. The key issue is how well the assets would be run under public ownership. What is the party hoping to achieve that could not be done via smarter regulation?

This part of the debate has been obscured by endless quarrels over how much it would cost to nationalise rail, mail, water, energy and BT Openreach. On the cost score, the IFS report merely offered a factual two-part answer, one of which was necessarily imprecise.

Related: IFS warns Labour renationalisation may delay low-carbon economy