International cooperation behind the veil of uncertainty. The case of transboundary pollution

The complexities of international environmental problems are only poorly understood. Hence, decision makers have to negotiate about abatement measures even though they do not know the 'true' model of the ecological system and have only a rough idea about the costs and benefits of their action. It will be analysed to what extent this kind of 'model uncertainty' - where players do not only have incomplete information about the payoff functions of the other players, but also about their own payoff function - affects the prospects of international cooperation. Using a simple game- theoretic model, it is shown how countries can use the veil of uncertainty to hide their distributional interests. The arguments are based on a deviation from the common prior assumption, which seems particularly questionable in a setting comprising various countries with different cultural and scientific backgrounds. Finally the model will prove useful to quantitatively and qualitatively illustrate the role of model uncertainty in the negotiations of the first Sulphur Protocol signed to combat boundary acidification. 26 refs