There is a need for policy analysis to solve societal (e.g. poverty), economic (e.g. unemployment) and environmental problems (e.g. greenhouse gas emission reduction) and hence to identify the relating primary as well as secondary impacts. Based on computable general equilibrium (CGE) modeling techniques this thesis analyses two problems of global scale: First, effects of international agreements on small-open economies from the perspective of developing as well as industrialized countries are studied. Second, this thesis focuses on the reduction of transport volume and related greenhouse gas emissions to achieve policy targets such as the EU 20-20-20 targets. CGE models are a standard tool and widely used in policy analysis to investigate ? among others ? macroeconomic, distributional and environmental effects. Within four publications, which span the research focus, this thesis studies: (1) effects of a trade liberalization on competitiveness and poverty in developing countries (for the example of Ecuador), (2) impacts of climate change agreements on competiveness of small open economies (for the example of Austria) and the risk of carbon leakage, (3) the potential of spatial planning options and transport policy to influence urban sprawl and to reduce transport volume and (4) policy options that foster technological change of alternative environmentally friendly passenger transport technologies and their resulting economic and environmental impacts. Each paper captures a different aspect of CGE modeling and all together extend existing modeling approaches and techniques manifold.