Quantitative Economics
Journal of the Econometric Society
Edited by: Bernard Salanié • Print ISSN: 1759-7323 • Online ISSN: 1759-7331
Edited by: Bernard Salanié • Print ISSN: 1759-7323 • Online ISSN: 1759-7331
Quantitative Economics: May, 2026, Volume 17, Issue 2
https://doi.org/10.3982/QE2369
p. 461-496
Simon Freyaldenhoven
Linear factor models are generally not identified. We provide sufficient conditions for identification: Under a natural sparsity assumption (the presence of local factors that affect only subsets of observables), the true loading matrix is the sparsest rotation and can be recovered by minimizing the ℓ1‐norm of the loading matrix. This enables economically meaningful interpretation of the individual factors. More generally, our ℓ1‐rotation criterion offers a novel approach to simplify the loading matrix and performs well relative to existing methods (e.g., Varimax, Kaiser (1958)) in our simulations. We illustrate our method in two economic applications. The R package l1rotation implements the method and facilitates adoption.
Simon Freyaldenhoven
This supplement contains material not found within the manuscript.
https://doi.org/10.5281/zenodo.17945084
Simon Freyaldenhoven
The replication package for this paper is available at https://doi.org/10.5281/zenodo.17945084. The Journal checked the data and codes included in the package for their ability to reproduce the results in the paper and approved online appendices.
July 5, 2026