The validity of Purchasing Power Parity (PPP) is re-examined using data for some emerging market economies and African countries, extending recent works of Doğanlar <italic>et al.</italic> (2009) and Chang <italic>et al.</italic> (2010), respectively. For this purpose, we apply new unit root tests that allow for nonlinearities...

This paper analyzes the validity of purchasing power parity (PPP) across twelve Central and Eastern European countries (CEECs). PPP is tested through linear and nonlinear unit root tests. The results suggest that when structural changes and nonlinearities are accounted for, the PPP hypothesis is...

In this paper, we examine the relationship between crude oil and natural gas prices. Using smooth transition regression modelling approach, we find that both the long-run and short-run relationships between oil and gas prices are more aptly modelled by simultaneous structural breaks and...