"This paper studies investment in health and human capital in a life cycle model. Health investment enhances survival to old age by improving health from its endowed level. The model predicts two distinctive phases of development. When income is low enough, the economy has no health investment...

In this paper we investigate the optimal scale of pay-as-you-go social security in a dynastic family model with human capital externalities, fertility and endogenous growth. Human capital externalities reduce the return to human capital investment and hence lead to under-investment in human...

"We examine a model in which an upstream firm can sell directly online and through heterogeneous intermediaries to heterogeneous consumers engaging in time-consuming search. Direct online sales may be more or less convenient and involve costly returns if the good fits consumers poorly. Direct...