[1] Univ Durham, Business Sch, Mill Hill Lane, Durham DH1 3LB, England
[2] MANIT, Natl Inst Technol, Dept Civil Engn, Bhopal 462003, MP, India
[3] Copenhagen Business Sch, Copenhagen Sch Energy Infrastruct CSEI, Dept Econ, Porcelaenshaven 16A, DK-2000 Frederiksberg, Denmark
[4] MANIT Bhopal, Natl Inst Technol, Dept Civil Engn, Environm Engn Div, Bhopal 462003, India