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Anderson-Rubin Wald test F(14,278)=3.29 P-val=0.0001 Anderson-Rubin Wald test Chi-sq(14)=46.28 P-val=0.0000 Stock-Wright LM S statistic Chi-sq(14)=18.34 P-val=0.1917 Will AR Wald/F and StockWright LM statistics always give consistent results? In what possible way, can one test perform better than the other to test robust weak instrument? Or in what situation can these two be inconsistent? Appreciated, Jingjing xi: ivreg2 employed (i.exogamy interaction emp_ratio = iv1 iv2 iv3_edu1 iv3_e > du2 iv3_edu3 iv3_edu4 iv4_edu1 iv4_edu2 iv4_edu3 iv4_edu4 edu1_msa edu2_msa e > du3_msa edu4_msa) exogamy_msa `missing' `control' `spouse' [pw=perwt], cluste > r(metaread) ffirst i.exogamy _Iexogamy_0-1 (naturally coded; _Iexogamy_0 omitted) i.age _Iage_19-62 (naturally coded; _Iage_19 omitted) i.edu _Iedu_0-4 (naturally coded; _Iedu_0 omitted) i.racesing _Iracesing_0-4 (naturally coded; _Iracesing_0 omitted) i.central _Icentral_0-2 (naturally coded; _Icentral_0 omitted) i.region _Iregion_11-42 (naturally coded; _Iregion_11 omitted) i.bpl_r _Ibpl_r_150-700 (naturally coded; _Ibpl_r_150 omitted) i.fe_age _Ife_age_19-54 (naturally coded; _Ife_age_19 omitted) i.fe_edu _Ife_edu_0-4 (naturally coded; _Ife_edu_0 omitted) i.fe_bpl_r _Ife_bpl_r_0-2 (naturally coded; _Ife_bpl_r_0 omitted) (sum of wgt is 1.7417e+06) Warning - collinearities detected Vars dropped: missing_iv2 missing_edu1_msa missing_edu2_msa missing_edu3_msa missing_edu4_msa missing_eng_msa missing_lny_msa missing_exogamymsa Summary results for first-stage regressions ------------------------------------------- Variable | Shea Partial R2 | Partial R2 | F( 14, 278) P-value _Iexogamy_1 | 0.0091 | 0.0072 | 11.53 0.0000 interaction | 0.0104 | 0.0086 | 15.71 0.0000 emp_ratio | 0.0222 | 0.0339 | 19.47 0.0000 NB: first-stage F-stat cluster-robust Underidentification tests Ho: matrix of reduced form coefficients has rank=K1-1 (underidentified) Ha: matrix has rank=K1 (identified) Kleibergen-Paap rk LM statistic Chi-sq(12)=42.51 P-val=0.0000 Kleibergen-Paap rk Wald statistic Chi-sq(12)=186.91 P-val=0.0000 Weak identification test Ho: equation is weakly identified Kleibergen-Paap Wald rk F statistic 13.28 See main output for Cragg-Donald weak id test critical values Weak-instrument-robust inference Tests of joint significance of endogenous regressors B1 in main equation Ho: B1=0 and overidentifying restrictions are valid Anderson-Rubin Wald test F(14,278)=3.29 P-val=0.0001 Anderson-Rubin Wald test Chi-sq(14)=46.28 P-val=0.0000 Stock-Wright LM S statistic Chi-sq(14)=18.34 P-val=0.1917 NB: Underidentification, weak identification and weak-identification-robust test statistics cluster-robust Number of clusters N_clust = 279 Number of observations N = 79686 Number of regressors K = 140 Number of instruments L = 151 Number of excluded instruments L1 = 14 IV (2SLS) estimation -------------------- Estimates efficient for homoskedasticity only Statistics robust to heteroskedasticity and clustering on metaread Number of clusters (metaread) = 279 Number of obs = 79686 F(139, 278) = 639.20 Prob > F = 0.0000 Total (centered) SS = 13667.47635 Centered R2 = 0.0638 Total (uncentered) SS = 62166.93622 Uncentered R2 = 0.7942 Residual SS = 12795.24587 Root MSE = .4007 ------------------------------------------------------------------------------ | Robust employed | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- _Iexogamy_1 | .6541899 .1993359 3.28 0.001 .2634987 1.044881 interaction | -.8226884 .3065279 -2.68 0.007 -1.423472 -.2219047 emp_ratio | .5106566 .1719288 2.97 0.003 .1736823 .8476308 exogamy_msa | .0004792 .0002147 2.23 0.026 .0000584 .0009001 ------------------------------------------------------------------------------ Underidentification test (Kleibergen-Paap rk LM statistic): 42.509 Chi-sq(12) P-val = 0.0000 ------------------------------------------------------------------------------ Weak identification test (Kleibergen-Paap rk Wald F statistic): 13.278 Stock-Yogo weak ID test critical values: 5% maximal IV relative bias 18.47 10% maximal IV relative bias 10.25 20% maximal IV relative bias 5.93 30% maximal IV relative bias 4.39 Source: Stock-Yogo (2005). Reproduced by permission. NB: Critical values are for Cragg-Donald F statistic and i.i.d. errors. ------------------------------------------------------------------------------ Hansen J statistic (overidentification test of all instruments): 12.670 Chi-sq(11) P-val = 0.3155 ------------------------------------------------------------------------------ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/