我相信,一个可以欺骗通过鲍姆 - 谢弗 - 斯蒂尔曼ivreg2
投入运行OLS具有双向集聚和互动正是如此:
. webuse nlswork
(National Longitudinal Survey. Young Women 14-26 years of age in 1968)
. ivreg2 ln_w grade c.age##c.ttl_exp tenure, cluster(idcode year)
OLS estimation
--------------
Estimates efficient for homoskedasticity only
Statistics robust to heteroskedasticity and clustering on idcode and year
Number of clusters (idcode) = 4697 Number of obs = 28099
Number of clusters (year) = 15 F( 5, 14) = 674.29
Prob > F = 0.0000
Total (centered) SS = 6414.823933 Centered R2 = 0.3206
Total (uncentered) SS = 85448.21266 Uncentered R2 = 0.9490
Residual SS = 4357.997339 Root MSE = .3938
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| Robust
ln_wage | Coef. Std. Err. z P>|z| [95% Conf. Interval]
----------------+----------------------------------------------------------------
grade | .0734785 .002644 27.79 0.000 .0682964 .0786606
age | -.0005405 .002259 -0.24 0.811 -.0049681 .0038871
ttl_exp | .0656393 .0068499 9.58 0.000 .0522138 .0790648
|
c.age#c.ttl_exp | -.0010539 .0002217 -4.75 0.000 -.0014885 -.0006194
|
tenure | .0197137 .0029555 6.67 0.000 .013921 .0255064
_cons | .5165052 .0529343 9.76 0.000 .4127559 .6202544
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Included instruments: grade age ttl_exp c.age#c.ttl_exp tenure
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只是可以肯定比较,为OLS系数:
. reg ln_w grade c.age##c.ttl_exp tenure
Source | SS df MS Number of obs = 28,099
-------------+---------------------------------- F(5, 28093) = 2651.79
Model | 2056.82659 5 411.365319 Prob > F = 0.0000
Residual | 4357.99734 28,093 .155127517 R-squared = 0.3206
-------------+---------------------------------- Adj R-squared = 0.3205
Total | 6414.82393 28,098 .228301798 Root MSE = .39386
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ln_wage | Coef. Std. Err. t P>|t| [95% Conf. Interval]
----------------+----------------------------------------------------------------
grade | .0734785 .0010414 70.55 0.000 .0714373 .0755198
age | -.0005405 .000663 -0.82 0.415 -.0018401 .0007591
ttl_exp | .0656393 .0030809 21.31 0.000 .0596007 .0716779
|
c.age#c.ttl_exp | -.0010539 .0000856 -12.32 0.000 -.0012216 -.0008862
|
tenure | .0197137 .0008568 23.01 0.000 .0180344 .021393
_cons | .5165052 .0206744 24.98 0.000 .4759823 .557028
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