Rome brain drain
One in every two people live in cities. Some 200 cities have a population of more than a million. Cities have almost always been centers of creativity, attracting artists of all genres. Paris was known for its painters, London for writers, New York for musicals. An exception to the city-creativity rule, however, was Rome.
Though the Renaissance flourished in Rome, almost all the famous architects, painters, sculptors, and musicians departed from Rome as soon as they had completed their projects.