Contents: Equilibrim models displaying endogenous fluctuations and chaos: a survey -- Periodic and aperiodic behaviour in discrete one - dimensional dynamical systems -- A characterization of erratic dynamics in the overlapping generations models -- On endogenous competitive business cycles -- Competitive business cycles in an overlapping generations -- Endogenous fluctuations in a two- sector overlapping generations economy with productive investment -- Resent theories of the business cycle : the role of speculative inventories -- Endogenous cycles with uncertain lifespans in continuous time -- The Hopf Bifuration and the existence and stability of closed orbits in multisector moels of optimal economic growth -- Sources of complex dynamics in two- sector growth models -- Imperfect financial intermediation and complex dynamics -- Dynamical systems that solve continuous - Time concave optimization problems -- Stochastic equilibrim oscillations -- Cyclical and choatic behaviour in a dynamic equilibrim model with implications for fiscal policy -- Endogenous business cycles with self - fulfillinf optimism: a model with entry -- Keynesian chaos -- Feedback between R&D and productive growth : a chaos model -- Is the business cycle characterized by deterministic chaos -- The statistical properties of dimensions calculations using small data sets: some economic application-- Some evidence on the Non- Linearity of economic time series -- Some evidence on the non- linearity of economic time series 1890-1981-- Nonlinear dynamics and stock returns.