The close ties of the IIASA Ecology Project with research institutions in France, the GDR, and Wisconsin permitted the collection of parallel legal documents dealing with environmental protection in the three regions. The IIASA team also obtained empirical values of pollution concentrations in the cities of each study area. This material provided a basis for a cross-national comparison of such factors as government roles in supervising industry, the chain of authority in the implementation of pollution legislation, pollution standards, and sanctions against polluters. Also, a preliminary attempt was made to assess each country's progress in executing its legislation, through examination of current concentrations of pollutants in the ambient air
