Kahn joined the University of Southern California (USC) as a professor of economics in 2015, and became chair of the department in 2017.
Their first publication together was a paper on the increasing number of highly educated young “power couples” moving to large cities.
21CC is Johns Hopkins University's center for research, teaching, and outreach on urban economic growth and quality of life.
[10] The initiative hosts workshops and symposiums, produces policy briefs, and fosters student research opportunities.
The initiative collects and analyses data to evaluate the effectiveness of policies on the local, state, and federal level.
[1] Kahn has published many papers and has authored nine books, including Green Cities: Urban Growth and the Environment (Brookings Institution Press, 2006) and (with Dora L. Costa) Heroes and Cowards: The Social Face of War, which was published late in 2008 by Princeton University Press.
[12] In May 2016, Princeton University Press published his book, Blue Skies over Beijing: Economic Growth and the Environment in China.
In February 2021, Johns Hopkins University Press will publish his co-authored book; Unlocking the Potential of Post Industrial Cities.