Document Type

Working Paper

Date

Spring 5-2015

Keywords

Averaged estimator, many weak instruments, class estimator, k-class estimator

Language

English

Disciplines

Analysis | Econometrics | Economics | Mathematics

Description/Abstract

We develop averaged instrumental variables estimators as a way to deal with many weak instruments. We propose a weighted average of the preliminary k-class estimators, where each estimator is obtained using different subsets of the available instrumental variables. The averaged estimators are shown to be consistent and to satisfy asymptotic normality. Furthermore, its approximate mean squared error reveals that using a small number of instruments for each preliminary k-class estimator reduces the finite sample bias, while averaging prevents the variance from inflating. Monte Carlo simulations find that the averaged estimators compare favorably with alternative instrumental-variable-selection approaches when the strength levels of individual IV are similar with each other.

ISSN

1525-3066

Additional Information

Working paper no. 180

wp180.pdf (505 kB)
Accessible PDF version

Source

Local input

Creative Commons License

Creative Commons Attribution 3.0 License
This work is licensed under a Creative Commons Attribution 3.0 License.

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