It is commonly believed that poverty in developing countries is a chronic structural phenomenon. Evidence from the small number of surveys conducted shows that many households move from poverty to wealth and back from one year to the next. This collection assembles six country studies which use household panel data to examine the issue of poverty. One set – based on panel data from China, Ethiopia, Pakistan and South Africa – looks at short-run poverty dynamics. A second set, drawing on data from Chile and Zimbabwe examines determinants of long-term economic mobility over periods of 14 years or more.