Key quote: "An abundance of small, independent firms is, along with January temperature and share of the population with college degrees, one of the best predic

Key quote: "An abundance of small, independent firms is, along with January temperature and share of the population with college degrees, one of the best predictors of urban growth." References cited: Abundance of small firms: http://www.economics.harvard.edu/faculty/glaeser/files/Clusters.pdf http://www.economics.harvard.edu/faculty/glaeser/files/Clust... Jan temp: http://www.economics.harvard.edu/pub/hier/2007/HIER2135.pdf http://www.economics.harvard.edu/pub/hier/2007/HIER2135.pdf College Degrees: http://www.economics.harvard.edu/pub/hier/2003/HIER2025.pdf http://www.economics.harvard.edu/pub/hier/2003/HIER2025.pdf