Wealth inequalities both within and between nations has reached an extreme point and is continuing to increase (Collier P. The bottom billion: why the poorest countries are failing and what can be done about it. Oxford University Press, New York, 2007; Henneberg S, The wealth gaps. Farmington Hills:...

This paper provides empirical evidence that there is no absolute convergence between the GDP per capita of the developing countries since 1950. Relying upon recent econometric methodologies (nonstationary long-memory models, wavelet models and time-varying factor representation models), we show...