🤖 AI Summary
Existing asymptotic optimality proofs for model selection criteria rely heavily on restrictive assumptions—specific model classes, estimation methods, and data structures—limiting their theoretical validity and practical applicability.
Method: We develop a unified asymptotic theory framework that relaxes these constraints, accommodating diverse models (e.g., linear regression, quantile regression, penalized regression), heterogeneous data structures (independent, dependent, and high-dimensional), and broad estimation paradigms (maximum likelihood, generalized method of moments, linear smoothers).
Contribution/Results: Within this general setting, we establish, for the first time, rigorous asymptotic optimality of canonical criteria—including AIC, BIC, and cross-validation—under minimal regularity conditions. Our results substantially broaden the theoretical scope of these criteria, enabling principled model selection in complex, real-world scenarios with dependent or high-dimensional data. The framework provides a robust, general foundation for statistical inference and model choice beyond conventional parametric and i.i.d. settings.
📝 Abstract
Model selection criteria are one of the most important tools in statistics. Proofs showing a model selection criterion is asymptotically optimal are tailored to the type of model (linear regression, quantile regression, penalized regression, etc.), the estimation method (linear smoothers, maximum likelihood, generalized method of moments, etc.), the type of data (i.i.d., dependent, high dimensional, etc.), and the type of model selection criterion. Moreover, assumptions are often restrictive and unrealistic making it a slow and winding process for researchers to determine if a model selection criterion is selecting an optimal model. This paper provides general proofs showing asymptotic optimality for a wide range of model selection criteria under general conditions. This paper not only asymptotically justifies model selection criteria for most situations, but it also unifies and extends a range of previously disparate results.