干旱区生态环境知识资源中心

Environmental and climatic changes can dramatically affect the long run demand and usefulness of large public transport infrastructures. Migrations, desertification, heavy weather conditions, rising in the sea level, floods, etc., are natural phenomenon difficult to estimate in their extent and timing that in the long run can have a significant impact on the use of highways, harbors, bridges, dams, rails, undergrounds, airports, etc.. Decisions about transport infrastructure projects have to be taken while future developments are uncertain. In general, they are implemented over several years, during which many factors can change significantly: technological advances, political shifts, economic fluctuations and so on. Moreover, transport infrastructure investments are usually highly costly and irreversible (in that the decision to realize the infrastructure involves costs that cannot be recouped, for example a railway track or a motorway). These uncertainties make such kinds of investment highly risky. Project managers and engineers are thus forced in embedding flexibilities in the infrastructures to cope with the increasing long run uncertainty posed by environmental, economic, social and climatic changes. Hence, flexibilities in transport investment projects, if any exist, are appreciable and valuable. Anyway, the traditional large infrastructure assessment process based on the net present value (NPV) is challenged since the value of the flexibility is rarely taken into proper consideration. We here propose to assess the value of the flexibilities any large public transport infrastructure project has through a real option analysis (ROA). A real option (RO) is the possibility that the management has to modify an investment during the course of its life to cope with the on-going development of the business. Differing from a fmancial option, it has no legal existence but relates directly to the real assets of the investment. From a capital budgeting perspective, coupling the classical NPV analysis with ROA can enhance the public investment decision process and facilitate decision makers' job. In practice, real options are difficult to recognize and to price properly. Since the pioneering work of Myers (1977) ROA for private companies' project valuation has been largely studied from the corporate finance perspective (Trigeorgis and Mason 1987, Ingersoll and Ross 1992, Amram and Kulatilaka 1998, Aguerreve 2003, Grenadier and Malenko 2010, to cite just a few among the copious relevant literature) and taken into proper account by analysts and practitioners of the private sector. Anyway, real options seem not yet to have received the attention that they deserve in the decision process of public infrastructure investment projects, either in theory or in practice. We conclude that coupling the classical NPV analysis with ROA enhance the public investment decision process and facilitate decision makers' job.