a feedback model for the evolution of civilizations

The paper proposes a simple feedback model capable of explaining the evolution of various civilizations as determined by historians and scientists. The forward path of this feedback model consists of a first-order system, accounting for an accumulation process, in series with a pure time delay, and its feedback path consists of a constant possibly preceded by a filter. To account for an eventual decline, a smoothed derivative term can also be added. It is shown how the evolution pattern depends on few model parameters susceptible to interesting interpretations, thus providing a powerful "tool for thought". The relation of the suggested model with the Phillips model of a closed economy is also pointed out