Decision Sciences Journal
Volume 29, Number 4
Fall 1998
Effect of Level of Disaggregation on Conjoint Cross Validations:
Some Comparative Findings
Abba M. Krieger
Statistics Department, University of Pennsylvania, Philadelphia,
PA 19104, email: abba@stat.wharton.upenn.edu
Paul E. Green
Marketing Department, University of Pennsylvania, Philadelphia,
PA 19104, email: greene@wharton.upenn.edu
U. N. Umesh
Department of Marketing, Washington State University, Vancouver,
WA 98686
Abstract. Early formulations of conjoint models focused
on part-worth estimation at the individual level. As the methodology’s
popularity grew so did industry demands for increasingly larger
numbers of attributes and levels. In response to these demands,
new approaches, based on partial or full data aggregation (such
as clusterwise/latent class conjoint and choice-based conjoint),
have appeared. This paper suggests that pooled-data models will
often be successful in predicting market shares when researchers
employ monotonic attributes. In these cases more of a good attribute
(or less of a bad attribute) is always more preferred. In the
more realistic case, in which some of the attributes may be nonmonotonic,
we find that data aggregation does not predict holdout sample
preferences as well as individual part-worth models.
Subject Areas: Marketing and Preference Measurement. |