This thesis consists of an introductory chapter and four papers, which relate to environmental policy in the presence of transboundary environmental damage. Paper [I] concerns public policy in a multi-jurisdiction framework with transboundary environmental damage. Each jurisdiction is assumed large in the sense that its government is able to infuence the world-market producer price of the externality-generating good. This gives rise to additional incentives of relevance for national public policy in the non-cooperative Nash equilibrium. With the uncoordinated equilibrium as the reference case, the welfare effects from coordinated changes in public policy variables are analyzed. Paper [II] analyses welfare effects of coordinated changes in environmental and capital taxation in the presence of transboundary environmental externalities and wage bargaining externalities. In the wage bargaining between frms and labor unions, firms use the threat of moving abroad to moderate wage claims, which means that domestic policy infuences wage formation abroad. The specific framework implies welfare effects of policy coordination that correspond to each of the respective international interaction mentioned above. In paper [III], national governments face political pressure from environmental and industrial lobby groups, while pollution taxes are determined in an international negotiation. It is shown that a general increase in the environmental concern and the weight the governments attach to social welfare both tend to increase the pollution tax. However, allowing for asymmetries between the countries means that a general increase in the environmental concern has the potential to reduce the pollution tax. Paper [IV] studies national environmental policies in an economic federation characterized by decentralized leadership. The federal government sets emission targets for each member country, which are implemented by the national governments. Although all national governments have commitment power vis-à-vis the federal government, one of them also has commitment power vis-à-vis the other member countries. This creates incentives to act strategically toward the federal government, as well as toward other members.

<p>This thesis consists of a summary and four papers. The first two papers address political economy and indus-trial organization aspects of agricultural policy, and the last two international aspects of environmental policy.</p><p>Paper [I] explains Common Agricultural Policy (CAP) subsidies to farmers by the influence of farmer interest-groups with an EU-wide membership. The analysis is based on panel-data for fifteen commodities over the period 1986-2003. Because the CAP is set as an overall EU policy, effective lobbying presents a collective ac-tion problem to the farmers in the EU as a whole. Indicators of lobbying, which are based on this perception, are found to explain part of the variation in agricultural support.</p><p>In Paper [II], the Bresnahan-Lau framework is used to analyze whether policy reforms, i.e. the two-price sys-tem (an input quota, 1986-1991) and a general deregulation of dairy policy (1991-1994) had any market power effects on the Swedish butter market. The results show that the null hypothesis of no market power cannot be rejected, for any of the specific policy reforms, at any reasonable significance level.</p><p>Paper [III] concerns the welfare consequences of environmental policy cooperation. It is assumed that coun-tries finance their public expenditures by using distortionary taxes, and that they differ with respect to compe-tition in the labor market. It is shown how the welfare effect of an increase in the expenditures on abatement depends on changes in the environmental damage, employment and work hours. The welfare effect is also related to the strategic interaction among the countries in the prereform equilibrium.</p><p>In Paper [IV] environmental policy in an economic federation, where each national government faces a mixed tax problem, is addressed. It is assumed that the federal government sets emission targets, which are imple-mented at the national level. It is also assumed that the economic federation is decentralized. The results high-light a strategic role of income and commodity taxation, i.e. each country uses its policy instruments, at least in part, to influence the emission target.</p>

This thesis consists of a summary and four papers. The first two papers address political economy and indus-trial organization aspects of agricultural policy, and the last two international aspects of environmental policy. Paper [I] explains Common Agricultural Policy (CAP) subsidies to farmers by the influence of farmer interest-groups with an EU-wide membership. The analysis is based on panel-data for fifteen commodities over the period 1986-2003. Because the CAP is set as an overall EU policy, effective lobbying presents a collective ac-tion problem to the farmers in the EU as a whole. Indicators of lobbying, which are based on this perception, are found to explain part of the variation in agricultural support. In Paper [II], the Bresnahan-Lau framework is used to analyze whether policy reforms, i.e. the two-price sys-tem (an input quota, 1986-1991) and a general deregulation of dairy policy (1991-1994) had any market power effects on the Swedish butter market. The results show that the null hypothesis of no market power cannot be rejected, for any of the specific policy reforms, at any reasonable significance level. Paper [III] concerns the welfare consequences of environmental policy cooperation. It is assumed that coun-tries finance their public expenditures by using distortionary taxes, and that they differ with respect to compe-tition in the labor market. It is shown how the welfare effect of an increase in the expenditures on abatement depends on changes in the environmental damage, employment and work hours. The welfare effect is also related to the strategic interaction among the countries in the prereform equilibrium. In Paper [IV] environmental policy in an economic federation, where each national government faces a mixed tax problem, is addressed. It is assumed that the federal government sets emission targets, which are imple-mented at the national level. It is also assumed that the economic federation is decentralized. The results high-light a strategic role of income and commodity taxation, i.e. each country uses its policy instruments, at least in part, to influence the emission target.