On stationarity and cointegration of international health expenditure and GDP

Abstract

The recent findings by McCoskey and Selden (1997, Journal of Health Economics, forthcoming) that health expenditure and GDP are stationary are driven by the omission of time trends in their ADF regressions. Since both health expenditure and GDP are trending, this omission raise serious doubts on the validity of their results. We apply recently developed heterogeneous panel tests which indicate that both health expenditure and GDP are nonstationary and cointegrated around linear trends. Additionally, we find weak evidence for the existence of a common cointegrating vector across the OECD countries.