Economic fluctuations and possible non-linear relations between macroeconomic variables for Brazil

The correctness of the macroeconomic prospective evaluations for planning a ctivities, mainly for capital intensive sectors, such as electricity supply , may represent the key between the success or failure of any kind of money -spending scheme, Macroeconomical results derived from government models ex hibit, in general, excessive optimistic growth and do not take into account "natural" fluctuations and other "explicit time-dependent events" found in any economical system. Such "quasi-deterministic" phenomena are derived fr om non-linear systems properties, like biological and "highly viscous" syst ems. This paper shows how this kind of "natural" process can be represented by this approach, which embodies two distinct behaviours observed in Brazi lian historical data: the systematic capital productivity decline and the o scillatory mechanism in the GDP production. This mathematical model represe nts one possible mechanism, which explain the macroeconomic variables behav iour. The oscillatory period obtained by this approach is close to that obs erved historically. For practical prospective purposes, an empirical model is also presented, (C) 2001 Elsevier Science B.V. All rights reserved.