The Best Things in Life are (Nearly) Free is a CGD Working Paper. The health of the world’s population—including those in the poorest countries—has improved more in the past 100 years than ever before. The improvement is largely a result of the development and spread of cheap, effective technologies (such as vaccines). Other factors, such as national wealth and institutional development, appear to be secondary, suggesting that exogenous models of development may still be relevant in explain gains in global health. In this paper, background to Kenny’s book Getting Better, the authors investigate the cross-country determinants of health improvements and describe the implications for development policy. In short, improving health need not be expensive. Even very poor countries can make great strides with good technologies and good delivery, but it may take time. Historical trends suggest we should not expect too much too quickly. A later version has been published in World Development.