To call this book ambitious is an understatement. The author offers a unified account of the development of living standards over the course of human history. Galor attributes the stagnation of incomes for 99 percent of history to the Malthusian trap—to the tendency for populations to grow in response to technological progress that raises incomes, putting pressure on the land until living standards fall back to subsistence levels. But he also links the acceleration of technological progress to population growth, arguing that more people made for more inventors and more successful inventions. As technological progress accelerated, societies reached a tipping point. Parents realized that to succeed in a quickly changing world, their offspring had to be equipped with education and skills to enable them to adapt; this expensive investment in children in turn required fertility control. From this point, population growth no longer responded positively to technological progress, and living standards took off. The argument ranges over the roles of culture, institutions, and genetics in economic development and underdevelopment. One need not agree with the author that his framework is entirely novel to be provoked.