The key hypothesis of this paper is that time use data bases make possible a broader view of the benefits and costs of human capital than is otherwise possible. This achievement is enabled by a set of integrated information on not only educational attainment but also on time devoted to formal and informal study, to paid and unpaid work of economic value, to work of civic value, to leisure activities, and to the educating of children by parents. It is argued that such information is central to human capital theory, though much of it, especially on the leisure costs of investment in human capital, has been hitherto ignored. This new information is important because it can be used to inform the debate over the key issues in this field -- for example, the value of increased public support to formal education -- by measuring previously overlooked aspects of the benefits and costs of investment in human capital.
