Hostname: page-component-8448b6f56d-m8qmq Total loading time: 0 Render date: 2024-04-23T13:36:36.224Z Has data issue: false hasContentIssue false

A NEW STUDY ON ASYMPTOTIC OPTIMALITY OF LEAST SQUARES MODEL AVERAGING

Published online by Cambridge University Press:  14 April 2020

Xinyu Zhang*
Affiliation:
Academy of Mathematics and Systems Science Chinese Academy of Sciences
*
Address correspondence to Xinyu Zhang, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing100190, China; e-mail: xinyu@amss.ac.cn.

Abstract

In this article, we present a comprehensive study of asymptotic optimality of least squares model averaging methods. The concept of asymptotic optimality is that in a large-sample sense, the method results in the model averaging estimator with the smallest possible prediction loss among all such estimators. In the literature, asymptotic optimality is usually proved under specific weights restriction or using hardly interpretable assumptions. This article provides a new approach to proving asymptotic optimality, in which a general weight set is adopted, and some easily interpretable assumptions are imposed. In particular, we do not impose any assumptions on the maximum selection risk and allow a larger number of regressors than that of existing studies.

Type
MISCELLANEA
Copyright
© Cambridge University Press 2020

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

We thank two anonymous referees, the Co-Editor, the Editor Peter C.B. Phillips, Tie Xie, and Jiahui Zou for many constructive comments and suggestions. Zhang gratefully acknowledges the research support from National Natural Science Foundation of China (grant numbers 71925007, 71631008, and 11688101). All errors remain the author.

References

REFERENCES

Ando, T. & Li, K.C. (2014) A model-averaging approach for high-dimensional regression. Journal of the American Statistical Association 109, 254265.CrossRefGoogle Scholar
Andrews, D. (1991) Asymptotic optimality of generalized C L, cross-validation, and generalized cross-validation in regression with heteroskedastic errors. Journal of Econometrics 47, 359377.CrossRefGoogle Scholar
Cheng, T.-C.F., Ing, C.K., & Yu, S.-H. (2015) Toward optimal model averaging in regression models with time series errors. Journal of Econometrics 189, 321334.Google Scholar
Claeskens, G., Croux, C., & van Kerckhoven, J. (2006) Variable selection for logistic regression using a prediction-focused information criterion. Biometrics 62, 972979.Google ScholarPubMed
Gao, Y., Zhang, X., Wang, S., Chong, T.T.-L., & Zou, G. (2019) Frequentist model averaging for threshold models. Annals of the Institute of Statistical Mathematics 71, 275306.CrossRefGoogle Scholar
Hansen, B.E. (2007) Least squares model averaging. Econometrica 75, 11751189.CrossRefGoogle Scholar
Hansen, B.E. (2014) Model averaging, asymptotic risk, and regressor groups. Quantitative Economics 5, 495530.CrossRefGoogle Scholar
Hansen, B.E. & Racine, J. (2012) Jackknife model averaging. Journal of Econometrics 167, 3846.CrossRefGoogle Scholar
Juditsky, A. & Nemirovski, A. (2000) Functional aggregation for nonparametric regression. Annals of Statistics 28, 681712.CrossRefGoogle Scholar
Kuersteiner, G. & Okui, R. (2010) Constructing optimal instruments by first-stage prediction averaging. Econometrica 78, 697718.Google Scholar
Li, K.-C. (1987) Asymptotic optimality for C p, C L, cross-validation and generalized cross-validation: Discrete index set. Annals of Statistics 15, 958975.CrossRefGoogle Scholar
Liu, C.-A. & Tao, J. (2016) Model selection and model averaging in nonparametric instrumental variables models. Working paper.Google Scholar
Liu, Q. & Okui, R. (2013) Heteroskedasticity-robust C p model averaging. The Econometrics Journal 16, 463472.CrossRefGoogle Scholar
Liu, Q., Okui, R., & Yoshimura, A. (2016) Generalized least squares model averaging. Econometric Reviews 35, 16921752.CrossRefGoogle Scholar
Racine, J. (1997) Feasible cross-validatory model selection for general stationary processes. Journal of Applied Econometrics, 12 169179.3.0.CO;2-P>CrossRefGoogle Scholar
Rao, C.R. (1973) Linear Statistical Inference and its Applications, vol. 2. Wiley, New York, NY.CrossRefGoogle Scholar
Wan, A.T.K., Zhang, X., & Zou, G. (2010) Least squares model averaging by Mallows criterion. Journal of Econometrics 156, 277283.CrossRefGoogle Scholar
Wiens, D.P. (1992) On moments of quadratic forms in non-spherically distributed variables. Statistics 23, 265270.CrossRefGoogle Scholar
Xie, T. (2015) Prediction model averaging estimator. Economics Letters 131, 58.CrossRefGoogle Scholar
Xie, T. (2017) Heteroscedasticity-robust model screening: A useful toolkit for model averaging in big data analytics. Economics Letters 151, 119122.Google Scholar
Yang, Y. (2004) Combining forecasting procedures: Some theoretical results. Econometric Theory 20, 176222.CrossRefGoogle Scholar
Yuan, Z. & Yang, Y. (2005) Combining linear regression models: When and how? Journal of the American Statistical Association 100, 12021214.CrossRefGoogle Scholar
Zhang, X. (2010) Model averaging and its applications. Ph.D. Thesis, Academy of Mathematics and Systems Science, Chinese Academy of Sciences.Google Scholar
Zhang, X., Lu, Z., & Zou, G. (2013a) Adaptively combined forecasting for discrete response time series. Journal of Econometrics 176, 8091.CrossRefGoogle Scholar
Zhang, X., Wan, A.T., & Zou, G. (2013b) Model averaging by jackknife criterion in models with dependent data. Journal of Econometrics 174, 8294.CrossRefGoogle Scholar
Zhang, X., Zou, G., and Carroll, R.J. (2015) Model averaging based on Kullback-Leibler distance. Statistica Sinica 25, 1583.Google ScholarPubMed