Efficient GMM with nearly-weak instruments
This paper is in the line of the recent literature on weak instruments, which, following the seminal approach of Stock and Wright captures weak identification by drifting population moment conditions. In contrast with most of the existing literature, we do not specify a priori which parameters are strongly or weakly identified. We rather consider that weakness should be related specifically to instruments, or more generally to the moment conditions. In addition, we focus here on the case dubbed nearly-weak identification where the drifting DGP introduces a limit rank deficiency reached at a rate slower than root-T. This framework ensures the consistency of Generalized Method of Moments (GMM) estimators of all parameters, but at a rate possibly slower than usual. It also validates the GMM-LM test with standard formulas. We then propose a comparative study of the power of the LM test and its modified version, or K-test proposed by Kleibergen. Finally, after a well-suited rotation in the parameter space, we identify and estimate directions where root-T convergence is maintained. These results are all directly relevant for practical applications without requiring the knowledge or the estimation of the slower rate of convergence. Copyright (C) The Author(s). Journal compilation (C) Royal Economic Society 2009
If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
As the access to this document is restricted, you may want to look for a different version under "Related research" (further below) or search for a different version of it.
Volume (Year): 12 (2009)
Issue (Month): s1 (01)
|Contact details of provider:|| Postal: |
Phone: +44 1334 462479
Web page: http://www.res.org.uk/
More information through EDIRC
|Order Information:||Web: http://www.ectj.org|
When requesting a correction, please mention this item's handle: RePEc:ect:emjrnl:v:12:y:2009:i:s1:p:s135-s171. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Wiley-Blackwell Digital Licensing)or (Christopher F. Baum)
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.
Please note that corrections may take a couple of weeks to filter through the various RePEc services.