Nonlinear demographic models and chaotic demo-dynamics

Blanchet (Didier). - Nonlinear demographic models and chaotic demo-dynamics The development of nonlinear models is undoubtedly a promising field for demographic modelling (Feichtinger, 1993). Linear models derived from stable population theory still remain a basic reference, but it is clear that nonlinear models offer much more possibilities to account for actual demographic or demoeconomic dynamics. On the other hand, there is one aspect of nonlinear models which has been probably overemphasized over the last years, which is their ability to generate chaotic dynamics. Up to now, models which have been proposed have some difficulties in deriving such a behavior from plausible assumptions concerning demographic behavior or demo-economic relationships. We illustrate this point of view by discussing two examples, borrowed respectively from Day (1984) and Prskawetz/Feichtinger (1995). Research on this topic can go on, but should pay a particular attention to the realism of assumptions used to build these models.