摘要：The core of the book is devoted to illustrating the central problem of over-optimism in ex ante evaluations, and discussing the characteristics of the policy process that generate systematic bias on the part of project proponents. The authors make a range of useful suggestions In addition to the core point regarding overestimation of benefits, the book offers useful discussion of environmental aspects of the megaproject process, and of the costs and benefits of private provision of infrastructure. As regards environmental issues, little has changed since the introduction of environmental impact assessments in the 1970s. Typically, these occur in the middle of the process, after the design phase, and before construction begins. The authors argue for more consistent attention to environmental issues beginning in the design phase and ending with ex post assessments of actual, as compared to predicted, environmental impacts.
