In this article we test the random walk hypothesis in the Spanish daily stock market prices by means of using fractionally integrated techniques. We use a version of the tests of Robinson (1994) that permit us to test I(d) statistical models. The results show that though fractional degrees of...

In this article we propose a new method for testing nonstationary cycles in financial time series data. In particular, we use a procedure due to Robinson (1994) that permits us to test unit root cycles in raw time series. These tests have several distinguishing features compared with other...

This paper identifies structural breaks in the post-World War II joint dynamics of U.S. inflation, unemployment and the short-term interest rate. We derive a structural break-date procedure which allows for long-memory behavior in all three series and perform the analysis for alternative data...

We propose in this article a two-step testing procedure of fractional cointegration in macroeconomic time series. It is based on Robinson’s (1994) univariate tests and is similar in spirit to the one proposed by Engle and Granger (1987), testing initially the order of integration of the...

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...

This paper deals with the presence of long range dependence at the long run and the cyclical frequencies in macroeconomic time series. We use a procedure that allows us to test unit roots with fractional orders of integration in raw time series. The tests are applied to an extended version of...

This paper deals with the analysis of structural breaks in the context of fractionally integrated models. We assume that the break dates are unknown and that the different sub-samples possess different intercepts, slope coefficients and fractional orders of integration. The procedure is based on...

This paper proposes a model of the US unemployment rate which accounts for both its asymmetry and its long memory. Our approach introduces fractional integration and nonlinearities simultaneously into the same framework, using a Lagrange Multiplier procedure with a standard null limit...

This paper deals with the estimation of time trends in temperature anomaly series. However, instead of imposing that the estimated residuals from the time trends are I(0) stationary, we allow them to be fractionally integrated. In this context, a new procedure for testing fractional integration...

This paper deals with the analysis of the monthly structure of sunspot numbers using a new technique based on cyclical long range dependence. The results show that sunspot numbers have a periodicity of 130 months, but more importantly, that the series is highly persistent, with an order of...