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This study summarizes more than 15 years of scientific support for the United Nations-Economic Commission Europe (UN-ECE) Convention on Long Range Transboundary Air Pollution (LRTAP) and other European environmental protection conventions such as the Commission for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and the Baltic Marine Environment Protection Commission (HELCOM) by means of development and application of numerical simulation models for the atmospheric long-range transport of heavy metals. The work is mainly based on results and conclusions described in the nine papers of the appendix but some more recent investigations which have not yet been published in the scientific literature are also presented. An introductory overview and synthesis of current knowledge and understanding pertaining to all major aspects of heavy metals in the atmosphere is presented from a viewpoint that numerical modelling of their atmospheric processes is necessary and feasible to support the conventions mentioned above. The models discussed in this study have capabilities to quantify transboundary fluxes of lead, cadmium and mercury as the priority metals of concern and have a potential to identify sources as well as to predict the impact of emission reductions on the load of terrestrial and aquatic ecosystems in Europe. Advantages and limitations of relatively simple Lagrangian models are outlined within the context of issues currently facing the environmental scientific and policy making communities. However, a focus of this study is a comprehensive model system for atmospheric mercury species using a fully three-dimensional Eulerian reference frame and incorporating a state-of-science mercury chemistry scheme, which has been adopted by various scientific institutions for their modelling purposes.
Despite the scepticism raised by the German Monopoly Commission our analysis shows that the revised theory of contestable markets can be applied to the telecommunications market better than expected. The original contestable market theory implied three assumptions necessary to be satisfied to establish potential competition: Free market entry, market exits possible without any costs, and the price adjustment lag exceeds the entry lag. Our analysis shows that if the incumbent reduces its prices slowly (high adjustment lag) and the market entry can be performed quickly (low entry lag), a new competitor will be able to earn back sunk costs. Therefore it is not necessary that all three conditions are complied with for potential competition to exist. We applied the 'revised' contestable market theory to the German telecommunication market and have been able to clearly identify the sections in which regulation is required. Under the present conditions local loops - which should be seen as natural monopolies - are not contestable due to sunk costs, high entry lags expected and a probable short price adjustment lag. Local loops can be identified as bottlenecks therefore. Regional and local connection networks should also be regulated because a high entry lag and a low price adjustment lag have to be expected as well as current competition does not exist today. The national connection network shows current competition between several network providers, hence regulation can be abolished in this field. Moreover, services can be supplied by several firms, and we predict strong potential competition.. There are no arguments favouring a natural monopoly in the section of terminals.