Book excerpt: This Handbook presents the first comprehensive study of policy analytical practices in comparative perspective. It explores emerging developments and innovations in the field and advances knowledge of the nature and quality of policy analysis across different countries and at different levels of government by all relevant actors, both inside and outside government, who contribute to the diagnosis of problems and the search for policy solutions. Handbook chapters examine all aspects of the science, art and craft of policy analysis. They do so both at the often-studied national level, and also at the less well-known level of sub-national and local governments. In addition to studying governments, the Handbook also examines for the first time the practices and policy work of a range of non-governmental actors, including think tanks, interest groups, business actors, labour groups, media, political parties and non-profits. Bringing together a rich collection of cases and a renowned group of scholars, the Handbook constitutes a landmark study in the field.