This intriguing book measures social mobility in a novel way, by tracing unusual surnames over several generations in nine different countries, focusing on intergenerational changes in education, wealth, and social status as indicated by occupation. Two surprising generalizations emerge. The first is that social mobility is much lower than is usually supposed, even in the United States. The second is that social mobility does not differ greatly from country to country or over long periods of time, even in China, despite its radical communist revolution, or in Sweden and the United Kingdom, which since 1945 have deliberately promoted the goal of better mobility. (Notably, India, with its history of caste stratification, does show lower mobility than other countries.) Clark concludes that family talent, whether genetic or environmental in origin, persists over generations and reverts to the mean of the surrounding population very slowly. One implication he notes is that public measures to increase mobility are likely to be less effective and durable than policymakers assume. Another is that redistributive taxation is likely to have a less deleterious effect on an economy than many claim.