تست های واحد ریشه پنل برابری قدرت خرید برای شاخص قیمت

This paper adopts four panel unit root tests to evaluate PPP over the floating period for six different price indices. Results generally support PPP, albeit the speeds of adjustment differ considerably between price indices and test procedures. The degree of contemporaneous and serial correlation as well as heterogeneity of the series in the panel affect stationarity and the speed of mean reversion.