On the Universality of the Inner Product as a PMI Estimator in Embedding Models

Enrique Amigo, Fernando Giner, Julio Gonzalo


Abstract
Embedding representations are widely used in natural language processing, yet their semantic interpretation depends on the operators used to compare them. Previous work has shown that, for certain embedding models, the inner product is linearly correlated with Pointwise Mutual Information (PMI). However, this relation has so far been established only empirically or analytically for specific models.

In this work, we formally show that, under certain assumptions about distributional semantic embedding models, the inner product between embeddings approaches PMI. This theoretical result provides a more general explanation for the observed relationship and enables the formulation of training criteria aimed at learning embedding spaces in which operations between embeddings are semantically interpretable.
Anthology ID:
2026.findings-emnlp.1800
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
38472–38480
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1800/
DOI:
Bibkey:
Cite (ACL):
Enrique Amigo, Fernando Giner, and Julio Gonzalo. 2026. On the Universality of the Inner Product as a PMI Estimator in Embedding Models. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 38472–38480, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
On the Universality of the Inner Product as a PMI Estimator in Embedding Models (Amigo et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1800.pdf