Some countries are earlier than others in the development and introduction of environmental innovations. Often, the leadership in technological development is accompanied by a leadership in environmental policy. The book provides an analysis of lead markets for innovations such as fuel cells, photovoltaics, and others. Contributions of innovation economics, policy analysis and environmental economics are assessed regarding their potential to explain the leadership of single countries. The book depicts the policy frameworks that are favourable to the creation of such lead markets on the basis of theoretical considerations and case studies. Finally, recommendations for R and D policies, environmental and industrial policies are derived.