If city and civic leaders want an example of how instrumental the private sector can be in the transformation of a city, they can look at billionaire investor Dan Gilbert. Gilbert and his family of companies were highlighted during a Monday afternoon session for CityLab, a three-day conference at the GM Renaissance Center with participants from 156 cities across 27 countries. He sat down for a chat with Richard Florida, co-founder and editor at large of CityLab.com and senior editor of The Atlantic.