A ‘creative crescent’ of northern European countries is challenging the economic power of the United States and ‘old Europe,’ according to a new index which measures performance in the knowledge economy.

In The Rise of the Creative Class, Richard Florida analysed the factors which enabled economically successful US cities to attract and retain talent.

His key finding was that this new 'creative class' wanted to live in open and tolerant places. Tolerant societies are able to attract talented people who contribute to technological innovation.

In his latest research published by Demos, Florida uses a similar approach to rank the European Union countries alongside the US.