Álvarez Vázquez, Nelson Julio2023-06-212023-06-2119862255-5471https://hdl.handle.net/20.500.14352/65951This paper reconsiders the positive statement that from the point of víew of the applícatíons, deterministic processes do not seem to have very great interest and that classical Fourier methods faíl when applied to economic time series. The basic reason is in the transformation used to attain stationarity. A trend definition is proposed and empirical evidence in frequency domain is offered.engAtribución-NoComercial 3.0 Españahttps://creativecommons.org/licenses/by-nc/3.0/es/technical reporthttp://economicasyempresariales.ucm.es/working-papers-cceehttps://economicasyempresariales.ucm.es/working-papers-cceeopen accessAnalysis economicsAnálisis económicoEconometría (Economía)5302 Econometría