Among the many social protection strategies, microcredit has come to captivate not just the development aid industry, but the policy world as a revolutionary approach to enhancing development effectiveness. Virtually every development project now has a "microcredit component," and everyone from rural cattle herders in Zimbabwe to peasants in rural India is aware of what it is. Three decades on from its humble beginnings in Bangladesh as the brain child of a now noble laureate, it has grown to an estimated $70 billion a year industry including a wide breadth of different interventions, products and business models. Has microcredit led to strong and flourishing local economies, or more importantly, made a real difference in the lives of the poorest? What regimes govern the industry? If borrowers repay microloans does this automatically mean that microcredit is a useful intervention in poverty reduction and if it is marginally useful, is it cost-effective? These are among some of the most pressing questions currently being debated in the donor community about the long-term impacts of the microfinance industry and are just some of the questions that this Ashgate Research Companion seeks to address as it provides a comprehensive and authoritative state-of-the-art review of the sector.