The sudden collapse of the centrally planned economies of Central and Eastern Europe (CEE) and the former Soviet Union (FSU), has created economic and environmental disequilibria of historically unprecedented dimensions throughout the region, as well as a process of gradual transition from plan to market. This historical ‘experiment’ provides a unique opportunity to study economyÐenvironment interactions and the adjustment process towards a new equilibrium, as well as the implications for conventional and novel policy instruments under transitional conditions. The changes that have taken place have been so many and so large that they defy many of the tools of marginal analysis. Privatization, industrial restructuring, market competition, price reform, and trade liberalization among others have suddenly been introduced where none existed and have so radically altered the fundamentals of these economies that they could be considered as new economies rather than simply reformed economies. However, underlying these radical changes, are many legacies of the centrally planned economy that persist or change only gradually. Furthermore, not all countries in CEE and the FSU have reformed their economies at the same pace. The northern tier countries of CEE moved faster than the southern tier and the latter faster than most FSU republics.