In his book, Capital in the Twenty-First Century, Thomas Piketty demonstrates that capitalism produces income inequality. He shows that over several hundred years and across many nations the rate of return on capital exceeds the growth rate of market economies. Returns to most forms of labour do not keep up with economic growth. Piketty explains as well that when economic growth slows, the gap between capital's increase and the economy's growth expands. When this happens, inheritors of capital benefit relative to others. Piketty's study makes use of income tax and other records that have been systematically collected since the French Revolution and especially in the early part of the twentieth-century. His empirical and historical study covers much of Europe and the United States, as well as Japan and other countries. The cross-cultural and historical similarities in the rates of capital and economic growth are striking. They change only with major disruptions such as wars. Piketty's results contradict many theories of economic growth and development. For anthropologists, Piketty's coupling of inheritance with capital accumulation has implications for the role of kinship and marriage arrangements in relation to status. Given his view, however, that economy only means markets, Piketty has difficulty justifying ways to counter capitalism's inherent inequality. Anthropologists who hold a broader vision of material life as composed of both impersonal exchange and mutuality, may usefully enter this discussion to explain and justify ways to counteract market economy's inherent inequality and instability.