This project investigated the institutionalisation of multilateral environmental negotiations. In particular, using a game theoretical approach, the results achieved in international climate negotiations were explained in terms of the respective parties´ egoistic bargaining position. In what currently holds climate protection is traditionally characterised as global public good. In contradistinction to public good on the state or national level, no single authoritative entity is in place to force desired cooperative behavior of the stakeholders involved. Accordingly, sovereign states´ cooperation always happens on a bona fide basis. This represents a major aggravation of the already short-handed incentive structure posed by public goods. Throughout the nineties double tier coalition games were devised in order to generate voluntary cooperation. Based on neoclassical assumptions these models, however, arrive at rather dim prospects regarding the realisation of international cooperation. The project funded by the German Research Association (DFG) countered with the hypothesis that certain groups within society will indeed take fairness criteria into consideration (e.g. per capita emissions, proportional abatement efforts, etc.). Of course, such aspects revolving around the concept of fairness are immediately evident from the issue of proportionality between industrialised and developing world. Besides ubiquitous cost-benefit rationale a government, pressed by election cyclical concerns, will in addition have to take certain generally applied fairness measures into account. With respect to equity preferential incentive structures, as observed in experimental economics laboratory research (cf. Bolton und Ockenfels 2000), a non-cooperative game scheme was applied to international climate negotiations. Theoretical analyses showed that the consideration of fairness contributes to the explanation of cooperative behavior. In the case of heterogenous countries it was equally proposed that equity concerns promote cooperation. Nevertheless, this was shown to depend to a large degree on actual equity preferences. The third phase of the project analysed the empirical relevance of the theoretical results. This effort included a world-wide survey of agents involved in international climate policy. The analysis showed that equity issues are considered highly important in international climate negotiations and that the polluter-pays rule (i.e., the rule of equal ratio between abatement costs and emissions) and the accompanying poor losers rule (i.e., the rule of exemption due to GDP) are the most widely accepted equity principles.