Paul D. Allison is professor of sociology at the University of Pennsylvania, where he teaches advanced graduate courses on event history analysis, categorical data analysis, and structural equation models with latent variables. He is the author of seven books and more than sixty journal articles, and is also the founder and president of Statistical Horizons, a company that offers short seminars on numerous topics in statistics. A former Guggenheim fellow, Allison received the 2001 Lazarsfeld Award for distinguished contributions to sociological methodology, and was elected as a fellow of the American Statistical Association in 2010.