```r # fixed-effects model (study as fixed effect) > m2 <- feglm(share ~ ideology * aot * veracity * concord | study, dt1, vcov = ~ pid + stimulus, family = 'binomial') NOTE: 720 observations removed because of NA values (RHS: 720). > summary(m2) GLM estimation, family = binomial, Dep. Var.: share Observations: 46,512 Fixed-effects: study: 4 Standard-errors: Clustered (pid & stimulus) Estimate Std. Error t value Pr(>|t|) ideology 0.009914 0.046491 0.213244 8.3114e-01 aot -0.469684 0.040420 -11.620022 < 2.2e-16 *** veracity 0.668206 0.085219 7.841030 4.4687e-15 *** concord 0.379376 0.075525 5.023192 5.0820e-07 *** ideology:aot 0.123507 0.030692 4.024129 5.7187e-05 *** ideology:veracity -0.258941 0.076876 -3.368311 7.5630e-04 *** aot:veracity 0.394336 0.059059 6.676982 2.4391e-11 *** ideology:concord 0.127361 0.067198 1.895322 5.8050e-02 . aot:concord 0.078220 0.038303 2.042168 4.1135e-02 * # ?!? veracity:concord 0.185255 0.148045 1.251337 2.1081e-01 ideology:aot:veracity -0.184576 0.036588 -5.044659 4.5433e-07 *** ideology:aot:concord -0.070255 0.047108 -1.491372 1.3586e-01 ideology:veracity:concord -0.128268 0.128444 -0.998635 3.1797e-01 aot:veracity:concord -0.006352 0.070443 -0.090177 9.2815e-01 ideology:aot:veracity:concord -0.090438 0.089432 -1.011257 3.1189e-01 # no 4-way-interaction ```