For more than fifteen years Abhijit V. Banerjee and Esther Duflo have worked with the poor in dozens of countries spanning five continents, trying to understand the specific problems that come with poverty and to find proven solutions. Their book is radical in its rethinking of the economics of poverty, but also entirely practical in the suggestions it offers. Through a careful analysis of a very rich body of evidence, including the hundreds of randomized control trials that Banerjee and Duflo’s lab has pioneered, they show why the poor, despite having the same desires and abilities as anyone else, end up with entirely different lives. Through their work, Banerjee and Duflo look at some of the most surprising facets of poverty: why the poor need to borrow in order to save, why they miss out on free life-saving immunizations but pay for drugs that they do not need, why they start many businesses but do not grow any of them, and many other puzzling facts about living with less than 99 cents per day. POOR ECONOMICS argues that so much of anti-poverty policy has failed over the years because of an inadequate understanding of poverty. The battle against poverty can be won, but it will take patience, careful thinking and a willingness to learn from evidence. Banerjee and Duflo are practical visionaries whose meticulous work offers transformative potential for poor people anywhere, and is a vital guide to policy makers, philanthropists, activists and anyone else who cares about building a world without poverty.