Home > Publications . Search All . Browse All . Country . Browse PSC Pubs . PSC Report Series

PSC In The News

RSS Feed icon

Prescott says sex offender registries may increase recidivism by making offender re-assimilation impossible

Frey says rising numbers of younger minority voters mean Republicans must focus on fiscal not social issues

Work by Garces and Mickey-Pabello cited in NYT piece on lack of black physicians


Elizabeth Bruch wins Robert Merton Prize for paper in analytic sociology

Elizabeth Bruch wins ASA award for paper in mathematical sociology

Spring 2015 PSC newletter available now

Formal demography workshop and conference at UC Berkeley, August 17-21

Next Brown Bag

PSC Brown Bags will be back fall 2015

Interaction Terms in Nonlinear Models

Publication Abstract

Karaca-Mandic, P., Edward Norton, and B. Dowd. 2012. "Interaction Terms in Nonlinear Models." Health Services Research, 47(1): 255-274.

Objectives. To explain the use of interaction terms in nonlinear models. Study Design. We discuss the motivation for including interaction terms in multivariate analyses. We then explain how the straightforward interpretation of interaction terms in linear models changes in nonlinear models, using graphs and equations. We extend the basic results from logit and probit to difference-in-differences models, models with higher powers of explanatory variables, other nonlinear models (including log transformation and ordered models), and panel data models. Empirical Application. We show how to calculate and interpret interaction effects using a publicly available Stata data set with a binary outcome. Stata 11 has added several features which make those calculations easier. LIMDEP code also is provided. Conclusions. It is important to understand why interaction terms are included in nonlinear models in order to be clear about their substantive interpretation.

DOI:10.1111/j.1475-6773.2011.01314.x (Full Text)

Browse | Search : All Pubs | Next