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Models as Approximations I: Consequences Illustrated with Linear Regression

2 Pith papers cite this work. Polarity classification is still indexing.

2 Pith papers citing it
abstract

In the early 1980s Halbert White inaugurated a "model-robust'' form of statistical inference based on the "sandwich estimator'' of standard error. This estimator is known to be "heteroskedasticity-consistent", but it is less well-known to be "nonlinearity-consistent'' as well. Nonlinearity, however, raises fundamental issues because in its presence regressors are not ancillary, hence can't be treated as fixed. The consequences are deep: (1)~population slopes need to be re-interpreted as statistical functionals obtained from OLS fits to largely arbitrary joint $\xy$~distributions; (2)~the meaning of slope parameters needs to be rethought; (3)~the regressor distribution affects the slope parameters; (4)~randomness of the regressors becomes a source of sampling variability in slope estimates; (5)~inference needs to be based on model-robust standard errors, including sandwich estimators or the $\xy$~bootstrap. In theory, model-robust and model-trusting standard errors can deviate by arbitrary magnitudes either way. In practice, significant deviations between them can be detected with a diagnostic test.

years

2026 2

representative citing papers

Gaussian comparison above the median

math.ST · 2026-07-08 · accept · novelty 7.0

A centered Gaussian with smaller covariance assigns at least as much probability as one with larger covariance to any closed convex set with reference probability at least 1/2.

Stochastic Sensitivity Analysis for Matched Observational Studies

stat.ME · 2026-06-03 · unverdicted · novelty 7.0

Stochastic sensitivity analysis for matched studies finds worst-case conditional laws for hidden confounders instead of worst-case realizations, controlled by a sensitivity parameter that permits imperfect alignment with potential outcomes and yields higher robustness than conventional methods.

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Showing 2 of 2 citing papers.

  • Gaussian comparison above the median math.ST · 2026-07-08 · accept · none · ref 223 · internal anchor

    A centered Gaussian with smaller covariance assigns at least as much probability as one with larger covariance to any closed convex set with reference probability at least 1/2.

  • Stochastic Sensitivity Analysis for Matched Observational Studies stat.ME · 2026-06-03 · unverdicted · none · ref 222 · internal anchor

    Stochastic sensitivity analysis for matched studies finds worst-case conditional laws for hidden confounders instead of worst-case realizations, controlled by a sensitivity parameter that permits imperfect alignment with potential outcomes and yields higher robustness than conventional methods.