[1] Univ Oxford, New Coll, Oxford OX1 2JD, England
[2] Oxford Inst Energy Studies, Oxford, England
[3] Univ Oxford St Antonys Coll, Dept Econ, Polit Econ Financial Markets Programme, Balliol Coll, Oxford OX1 3BJ, England
[4] Univ Oxford, Oxford Martin Sch, INET, Eth & Econ Programme, Oxford OX1 2JD, England
[5] Australian Natl Univ, Crawford Sch Publ Policy, Canberra, ACT 0200, Australia
[6] Ctr Econ Policy Res, Oxford, England