This paper investigates whether trade frictions, in the form of exchange controls, are among the main obstacles preventing the Purchasing Power Parity (PPP) hypothesis from being valid among trading nations. It specifically looks at whether exchange controls - a type of trade friction - hinder...

This paper puts forward a general statistical model in the time domain based on the concept of fractional integration. More specifically, in the proposed framework instead of imposing that the roots are strictly on the unit circle, we also allow them to be within the unit circle. This approach...

This note puts forward a new modelling approach that includes both fractional integration and autoregressive processes in a unified framework. The proposed model is very general and includes other more standard approaches such as the AR(F)IMA models. Some Monte Carlo evidence shows that the...