The project had set itself the goal to find out whether and, if so, at what level of regulations do environmental policies converge in developed countries and have an impact especially on international institutions and international trade for a possible convergence in environmental policy. For this aim, the development of forty environmental measures in 21 European countries, the USA, Mexico and Japan in the period from 1970 to 2000 as well as possible explanations for this development in a statistical analysis were initially investigated. In order to measure the convergence, two new methodological procedures were developed and applied.

The so-called "pair comparison" compares and aggregates the convergence of policies between all paired of countries.

The so-called "gap approach" measures the decrease or increase of distances in strict regulation to the strictest regulation. In addition the theoretical model, obtained in the quantitative analysis of the findings and the possible explanations, was refined in the case studies. In the case studies the development of six selected environmental policies in four countries was comparatively investigated.

The results of the statistical analysis show not only that the environmental policies strongly converged in the countries studied from 1970 to 2000, but also that it has increased the level of regulation - contrary to the widespread assumption in the discussion on the impact of globalization. Among the tested explanatory variables, the international legally binding harmonization had the strongest explanatory power at a comparable level of international communication of environmental policies.
The intensity of international trade between states and their economic integration into international markets, however, played a comparatively minor role. Of the national explanatory factors, the level of prosperity affected the convergence of environmental policies the most, whereas the pressure of the environmental problem and the articulation of environmental interests influenced the convergence weakly.
The case studies confirmed these results largely and also showed that international harmonization was often only the final step in a process of convergence, driven mainly by the international communication of environmental policies and international trade relations.