The contribution deals with a nonlinear dynamic macro-economic model which is used for simulation runs. Conditions and model specifications allowing for global stability are investigated and tested. Based on this some well-known facts as Schumpeterian long-wave phenomena, Keynesian unemployment, productivity growth effects are simulated. Moreover specifying an instrumental variable for state interventions policy issues are also discussed. With this runs it is shown that minor changes of parameters may provide totally different outcomes and different economic developments.