This article estimates a fractional integration model with nonlinear deterministic trends for the inflation rates of five African countries. The results indicate that nonlinearities are present in the case of Angola and Lesotho, but not in the case of Botswana, Namibia and South Africa....

This paper examines historical data on daily real wages in England for the time period 1260-1994 by means of new statistical techniques suitable for modelling long memory both at the long run and the cyclical frequencies. Specifically, it uses a procedure due to Robinson (1994) which is based,...

This article analyses the long memory properties of quarterly real output per capita in the US (1948Q1–2008Q3) using non-parametric, semi-parametric and parametric techniques. The results vary substantially depending on the methodology employed. Evidence of mean reversion is obtained in a...

This paper examines several US monthly financial time series using fractional integration and cointegration techniques. The univariate analysis based on fractional integration aims to determine whether the series are I(1) (in which case markets might be efficient) or alternatively I(d) with <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$$d...</equationsource></inlineequation>

This paper examines a version of the tests of Robinson (1994) that enables one to test models of the form (1-Lk)dxt = ut, where k is an integer value, d may be any real number, and ut is I(0). The most common cases are those with k = 1 (unit or fractional roots) and k = 4 and 12 (seasonal unit...