The disparity between the least and most productive regions in the UK is wide by the standards of many other OECD economies. An important factor is the concentration of public investment around London. The appraisal process for infrastructure investment projects follows the methodology set out in the Treasury’s Green Book. We argue that this methodology has reinforced the regional imbalance; that recent changes are unlikely by themselves to redress the London bias in infrastructure; and that infrastructure investments also need to be based on a strategic view about economic development for the whole of the UK.