EconBase
← All papers

The Panel Information Matrix Test

Martin Schumann

arXiv 8 Oct 2026 · Econometrics

arXiv:2610.12350 · PDF · Extracted main text

Abstract

The Information Matrix (IM) test is a natural specification check for likelihood-based models, yet cross-sectional implementations are often badly sized, confound neglected heterogeneity with distributional misspecification, and require third derivatives. We develop the panel information matrix (PIM) test for models with fixed effects. Explicit fixed effects isolate functional-form misspecification from time-invariant unobserved heterogeneity. Although the profile maximum likelihood estimator inherits incidental-parameter bias of order $O(1/T)$, the leading bias of the profile PIM is of order $\sqrt{n}/T$, so it is asymptotically negligible whenever $n/T^2\to 0$, which includes the rectangular regime $n/T\toconst$, and stabilizes under parabolic asymptotics $n/T^2\toρ\in(0,\infty)$. This robustness arises because the indicator fluctuates at rate $\sqrt{n}$ rather than $\sqrt{nT}$. The same rate argument makes third-derivative corrections asymptotically unnecessary, so the test uses only first- and second-order likelihood derivatives. Simulations confirm that asymptotic PIM critical values suffice in moderately long panels, even when Wald tests for $θ$ are badly sized, while a parametric bootstrap largely removes size distortions when $ρ>0$.

Citation extraction

45
references
108
in-text mentions
45
distinct cited
3
self-citations
6,311
main-text words

appendix boundary found by appendix_command · 23% of the source is main text. Read the extracted text to check this.

Most heavily cited references

The works this paper leans on most, across its whole bibliography — not restricted to papers in our corpus. Ranked by composite intensity, which combines how often a work is mentioned, how many sections mention it, and how much of that falls in the main text rather than the appendix.

ReferenceIntensityMentionsSectionsMain text
1Horowitz, Joel L (1994) Bootstrap-based critical values for the information matrix test0.9507486%
2White, Halbert (1982) Maximum likelihood estimation of misspecified models0.8746367%
3Jinyong Hahn and Guido Kuersteiner Bias reduction for dynamic nonlinear panel models with fixed effects0.8435460%
4Martin Schumann and Thomas A. Severini and Gautam Tripathi (2023) The role of score and information bias in panel data likelihoods self0.7547543%
5Jerzy Neyman and Elizabeth L. Scott Consistent estimation from partially consistent observations0.7373367%
6Chesher, Andrew (1984) Testing for neglected heterogeneity0.73732100%
7Lancaster, Tony (1984) The covariance matrix of the information matrix test0.73732100%
8Higgins, Ayden and Jochmans, Koen (2024) Bootstrap Inference for Fixed-Effect Models0.72713438%
9Jinyong Hahn and Whitney K. Newey Jackknife and analytical bias reduction for nonlinear panel models0.7218538%
10Aguirregabiria, Victor and Mira, Pedro (2007) Sequential Estimation of Dynamic Discrete Games0.64422100%

Showing the top 10 of 45 scored citations.