Unit root investigation with two breaks of Greek velocity

In the present article the time series of Greek velocity are investigated for the presence of a unit root and cycles , allowing for maximum two breaks which take place at an unknown point in time. This methodology is preferred to conventional Dickey & Fuller tests because the covered time horizon, namely from 1858 to 1938, is characterized by a number of very important events, the nature of which is either economic or historical. We use then the univariate spectral analysis to investigate the existens of cycles .(JEL: C12, C13, C22, C52).