Publication Type
Journal Article
Version
publishedVersion
Publication Date
1-2015
Abstract
We develop a method of testing linearity using power transforms of regressors, allowing for stationary processes and time trends. The linear model is a simplifying hypothesis that derives from the power transform model in three different ways, each producing its own identification problem. We call this modeling difficulty the trifold identification problem and show that it may be overcome using a test based on the quasi-likelihood ratio (QLR) statistic. More specifically, the QLR statistic may be approximated under each identification problem and the separate null approximations may be combined to produce a composite approximation that embodies the linear model hypothesis. The limit theory for the QLR test statistic depends on a Gaussian stochastic process. In the important special case of a linear time trend regressor and martingale difference errors asymptotic critical values of the test are provided. Test power is analyzed and an empirical application to crop-yield distributions is provided. The paper also considers generalizations of the Box-Cox transformation, which are associated with the QLR test statistic. (C) 2015 Elsevier B.V. All rights reserved.
Keywords
Box-Cox transform, Gaussian stochastic process, Neglected nonlinearity, Power transformation, Quasi-likelihood ratio test, Trend exponent, Trifold identification problem
Discipline
Econometrics
Research Areas
Econometrics
Publication
Journal of Econometrics
Volume
187
Issue
1
First Page
376
Last Page
384
ISSN
0304-4076
Identifier
10.1016/j.jeconom.2015.03.041
Publisher
Elsevier: 24 months
Citation
BAEK, Yae In; CHO, Jin Seo; and PHILLIPS, Peter C. B..
Testing linearity using power transforms of regressors. (2015). Journal of Econometrics. 187, (1), 376-384.
Available at: https://ink.library.smu.edu.sg/soe_research/2168
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Additional URL
https://doi.org/10.1016/j.jeconom.2015.03.041