Stocks: Transformation Takes Time

This chapter is about understanding the dynamics of nature, economy, and society. The concept of stocks presented here provides a productive perspective on these relationships. The stock perspective shows how things change over time and why some things react very slowly to change, thus are persistent. What initially sounds like just a simple description has a great practical significance: Only by understanding what changes how and especially how quickly, do we also understand what options for action arise. Furthermore, an analysis of stocks provides orientation with regard to the question of how much time we need to plan and implement changes. This also helps us understand where we should act as quickly as possible to initiate the necessary changes in time. We illustrate the concept at the example of the once dirtiest river in Germany, which for centuries served as the sewage channel of one of Germanys most densely populated and industrialized areas.