Group-based Trajectory Modeling Extended to Account for Nonrandom Participant Attrition

May 19, 2011

Haviland, A., Jones, B., & Nagin, D. (2011). Group-based Trajectory Modeling Extended to Account for Nonrandom Participant Attrition Sociological Methods & Research, 40 (2), 367-390 DOI: 10.1177/0049124111400041 


Daniel S. Nagin, Carnegie Mellon University, Pittsburgh, PA, USA,

Bobby L. Jones and Daniel S. Nagin Advances in Group-Based Trajectory Modeling and an SAS Procedure for Estimating Them Sociological Methods & Research 2007 35: 542-571.

February 7, 2010

This article is a follow-up to Jones, Nagin, and Roeder (2001), which described an SAS procedure for estimating group-based trajectory models. Group-based trajectory is a specialized application of finite mixture modeling and is designed to identify clusters of individuals following similar progressions of some behavior or outcome over age or time. This article has two purposes. One is to summarize extensions of the methodology and of the SAS procedure that have been developed since Jones et al. The other is to illustrate how group-based trajectory modeling lends itself to presentation of findings in the form of easily understood graphical and tabular data summaries.

Key Words: developmental trajectories • Proc Traj • finite mixture models