Poor people in developing countries are often affected by droughts, floods, illness, crop failure, job loss, and economic downturns. Informal insurance mechanisms provide some protection, but are weak in the face of major or recurring calamities. Most people cannot obtain formal insurance, and the lack of insurance and social protection therefore constrains investment, growth, and poverty reduction. Public action to remedy this deficiency is merited, but what form should it take? This book evaluates alternatives in widening insurance and social protection provision, including sustainability and poverty effects, in thorough, up-to-date thematic papers and case studies, development assessments, and policy analyses.