Poverty and Social Impact Analysis (PSIA) refers to the analysis of the distributional impact of policy reforms1 on the well-being or welfare of different stakeholder groups, with particular focus on the poor and vulnerable. This Sourcebook introduces a framework as well as tools for institutional, political, and social analysis (TIPS) in PSIA. It is intended primarily for practitioners who undertake policy analysis in developing countries. The Sourcebook provides illustrative guidance on a range of tools and their application; it does not seek to prescribe it to this audience. This Sourcebook is part of a growing and collaborative response by international agencies and national partners to encourage and provide more systematic poverty and social impact analysis; to build in-country capacity; and to shift the balance of PSIA experience from donors toward national stakeholders. More specifically, it is designed to fill a perceived gap in guidance on institutional, political, and social analyses and to complement the guidance provided in the World Bank’s User’s Guide to PSIA (2003), which advocates a multidisciplinary approach to PSIA and presents both economic and social tools and methods, along with the World Bank’s Economic Toolkit (Bourguignon and da Silva 2003). The Sourcebook also complements the reform-by-reform notes on economic analysis in PSIA, produced by the World Bank.