This study investigates the long-memory properties of the prices of three Kenyan commodities (tea, coffee and horticultural products) by applying fractional integration methods to monthly data spanning the period from August 1998 to December 2024. The empirical results provide evidence of...

This paper uses fractional integration methods to analyse the long-memory and persistence properties of inflation in the Shanghai Cooperation Organization (SCO) countries over the period from 1 January 1997 to 8 January 2025. This approach is more general than standard models based on the I(0)...

This paper investigates persistence in the MINT (Mexico, Indonesia, Nigeria, Turkey) stock markets applying fractional integration methods to daily data from 1 January 2022 to 31 October 2025. Different model specifications are estimated for prices, log prices and log returns under the...

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...