Identifying Behavioral Types
Christopher Kops, Paola Manzini, Marco Mariotti, Illia Pasichnichenko
TL;DR
This paper develops necessary and sufficient conditions for identifying the distribution of latent behavioral types from aggregate choice data, under minimal qualitative knowledge about how types map to alternatives. It shows that identifiability hinges on sufficient cross-type heterogeneity, formalized through combinatorial matchings between types and alternatives and through algebraic properties (nullspaces) of the type-level choice matrices. The authors introduce the type-state framework, deriving both matching-based and nullspace characterizations of generic and global identifiability, and extend the analysis to multiple choice occasions via tensor decomposition theory. Applications to vectors of characteristics and incomplete preferences illustrate the broad relevance and practical implications, including when aggregate data suffices to recover the underlying type distribution and, in some cases, the type-level probabilities themselves.
Abstract
We study identification in models of aggregate choice generated by unobserved behavioral types. An analyst observes only aggregate choice behavior, while the population distribution of types and their type-level choice patterns are latent. Assuming only minimal and purely qualitative prior knowledge of the process generating type-level choice probabilities, we characterize necessary and sufficient conditions for identifiability. Identification obtains if and only if the data exhibit sufficient cross-type behavioral heterogeneity, which we characterize equivalently through combinatorial matching conditions between types and alternatives, and through algebraic properties of the matrices mapping type-level to aggregate choice behavior.
