Various forms of instability can be observed in macroeconomic and financial data including changes in variance, changes in cycle properties, or both. Traditional tests do not allow to distinguish between these different cases. This paper proposes and compares two alternative approaches. The...

Owing to the vague fluctuation of energy prices from time to time, a new energy model, which considers both the mean-reverting behavior and the long memory property, is proposed in this paper. Since the problem of estimating parameters, in discrete time for this model, plays a central role in...

I consider a bivariate stationary fractional cointegration system and I propose a quasi-maximum likelihood estimator based on the Whittle analysis of the joint spectral density of the regressor and errors. This allows to estimate jointly all parameters of interest of the model. I lead a Monte...

Several governments in sub-Saharan Africa have embarked on various market reforms to improve commodity market performance. However, the success of such market reforms depends partly on the strength of the transmission of price signals between spatially separated markets and between different...

In this paper we discuss the calibration issues of power models built on mean-reverting processes combined with long memory. The unknown parameters of fractional mean-reversion processes are estimated by a hybrid estimation method, which is built upon the marriage of the quadratic variation and...

Price and liquidity puzzles have been identified as two major counterintuitive findings arising from monetary shocks. We investigate their presence in eleven African countries, using a dynamic stochastic general equilibrium model designed for indebted small open-economies. Our simulations reveal...