Recent advances in testing for the validity of Purchasing Power Parity (PPP) focus on the time series properties of real exchange rates in panel frameworks. One weakness of such tests, however, is that they fail to inform the researcher as to which cross-section units are stationary. As a...

Health economists have studied the determinants of the expected value of health status as a function of medical and nonmedical inputs, often finding small marginal effects of the former. This paper argues that both types of input have an additional benefit, viz. a reduced variability of health...