Gerald W. Scully is Professor of Economics in the School of Management at the University of Texas at Dallas, Richardson, USA. In 1996 he was Visiting Professor at the Inland Revenue Department, Wellington, New Zealand. Patrick James Caragata received his PhD in political economy from the University of Toronto in 1981. In June 1988 he moved to New Zealand and became chief economist at the Ministry of Energy where he redesigned the royalty regime for petroleum. His book Resource Pricing: Rent Recovery Options for New Zealand's Energy and Mineral Industries (1989) is now used as a standard refere...