Cities are the largest and most important man-made entities on Earth. They are simultaneously the root cause of many problems as well as the solutions to many of the challenges that face humanity. However, not every city has proven capable of solving those challenges. I like to look at cities as if they were living machines. I contemplate the fact that we built cities and then seemingly lost control of them. Politicians and city planners try to downplay that phenomenon and they attempt to give us the impression they have all the answers. They make us believe that they have the answers and that the situation is under control. But nothing could be further from the truth. This is why we have to discuss cities.

With more or less 4000 cities in the world having in excess of 100.000 inhabitants, one would think it would be easy to compare cities and maybe even learn from their successes as well as their failures. There are some online databases listing facts and figures but, the most trustworthy and usable information can be found on Google Earth. There are also plenty of lists offering rankings like “The top 100 cities to visit!” or, “The top 50 most attractive cities” or, the most affordable, bike-able, best to retire to cities in the world. With 4000 competitors it is easy to understand that most cities are not on any of these lists. Every publisher of such a list uses its own criteria. What are these criteria? Do they change over time? Do these criteria give us a hint about what a city can do to become successful and be on the list or are they only the result of it?