Is OECD real per capita GDP trend or difference stationary? Evidence from panel unit root tests

Panel unit root tests are used to evaluate if real per capita GDP for OECD economies are trend or difference stationary. The panel approaches require that the series in the panel are independent, but evidence from the correlation matrix of the residuals indicates dependence. The panel unit root procedures are thus adjusted to allow for correlation in the data using different approaches. There is overwhelming evidence that the OECD data are trend stationary using bootstrap methods that accommodate more general forms of serial and cross correlation in the data compared to the standard approach of subtracting cross sectional means.