AbstractWhy is there child labour? Are there arguments for abolishing or curtailing all forms of child labour, or just morally and physically dangerous ones like soldiering and prostitution? Given that at least some forms of child labour ought to be abolished or curtailed, which is the most effective way of doing it? The book tries to answer these questions both theoretically and empirically. Child labour can be inefficiently high or inefficiently low, but more likely the former. Market and government failure can lead to children being effectively sold into slavery. Even the most common and least objectionable forms of child work, helping parents on the family farm or with domestic chores, have harmful effects. The mechanisms that produce excessive child labour are the same that produce excessive fertility and infant mortality. There is no single remedy for child labour. A ban is unlikely to be effective on its own. The list of effective instruments includes not only obvious candidates like schools, credit, and cover against certain risks, but also less obvious ones like sanitation and preventive medicine. Even humdrum policies such as bringing electricity and piped water into people’s homes can significantly reduce child labour.