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Inference with Many Weak Instruments
DOI:10.1093/restud/rdab097.png)
Abstract
En 中文
We develop a concept of weak identification in linear instrumental variable models in which the number of instruments can grow at the same rate or slower than the sample size. We propose a jackknifed version of the classical weak identification-robust Anderson-Rubin (AR) test statistic. Large-sample inference based on the jackknifed AR is valid under heteroscedasticity and weak identification. The feasible version of this statistic uses a novel variance estimator. The test has uniformly correct size and good power properties. We also develop a pre-test for weak identification that is related to the size property of a Wald test based on the Jackknife Instrumental Variable Estimator. This new pre-test is valid under heteroscedasticity and with many instruments.
Keywords:
Instrumental variables
Weak identification
Dimensionality asymptotics
C12
C36
C55
Journal
IF:
6.4
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2.5K
Citations:
2.1W

