We analyze the first data set on consistently defined functional urban areas in Europe and compare the European to the US urban system. City sizes in Europe do not follow a power law: the largest cities are "too small" to follow Zipf's law.

In fiscally centralised countries with a unique country-wide income tax schedule, it is straightforward to quantify the degree of progressivity. In fiscally decentralised countries with varying local tax schedules, however, this is not the case. In these countries, the effective tax...