/* file name: haus_log.gss											August 1999	*/
/* Hausman test for the conflict model used in _Dirty Pool_ by Green, Kim, Yoon	*/
/* test 1: between pooled logit estimates and fixed effects logit estimates		*/
/* test 2: between pooled logit est's (with country dummies) and fe logit est's	*/

new;
k = 6; /* no. of regressors */

/* 			 H_0: no individual effects		H_1: heterogeneity 		*/
/* fe-logit	 consistent, inefficient		consistent				*/
/* pooled	 consistent, efficient			inconsistent			*/
/* regressors: contig lcaprat mingrow allied mindem mineco1 		*/

b_log = {	3.0420839,		/* pooled logit: estimates and covariance matrix */
		 	0.1016408,
			-.0171908,
			-.23360827,
			-.05746396,
			-.19398655	};

cv_log = {	0.00846075	.0002329	-.00006059	-.00447137	.00004624	-.00150137,
			0.0002329   .00057696	-1.789e-06	.00015589	-.00001289	.00023181,
			-.00006059  -1.789e-06   .00011889	.00014061	-4.626e-06	-.0000422,
			-.00447137  .00015589   .00014061   .00938963	.0000153	-.00004927,
			0.00004624  -.00001289  -4.626e-06  .0000153   	.00005208	-.00020422,
			-.00150137  .00023181   -.0000422  	-.00004927 -.00020422 	.00752966 	};

b_felog = {	1.9020388,		/* fixed effects logit */
			0.3868021,
			-.0589239,
			-1.0660345,
			-.0033458,
			-.07176932	};

cv_felog = { .11298584	-.0107876	-.00011601	-.0087571	.00023769	-.00163867,
			-.0107876   .01945629	-.00018838	-.00359275	-.00001446	.00183819,
			-.00011601  -.00018838   .00014196	-.00005462	.00001951	.00010707,
			-.0087571  	-.00359275  -.00005462   .18174291	-.00012116	-.00570813,
			.00023769  	-.00001446   .00001951  -.00012116  .00021595	-.00001771,
			-.00163867   .00183819   .00010707  -.00570813  -.00001771 	.03461275 	};

b_logc = {	3.6835907,  	/* pooled logit with country dummies */
			-.16020932,  
			-.05109361,   
			.18700663,   
			-.0454307,   
			-.2091766	};

cv_logc = {	.01701401	.0003292	-.00007093	-.00354091	.00003414	-.00276022,
			.0003292   	.00107456	1.193e-06	.00017402	-.00001139	.00061994,
			-.00007093  1.193e-06  	.00012459	-.00005551	6.523e-06	.00004403,
			-.00354091  .00017402  	-.00005551	.01509348	-.0001887	-.00203464,
			.00003414  	-.00001139  6.523e-06   -.0001887  	.00011268	-.00018527,
			-.00276022  .00061994   .00004403  	-.00203464  -.00018527 	.01626274 	};

"Hausman Test between pooled logit and FE logit:";
haus_stat1 = (b_felog - b_log)'inv(cv_felog - cv_log)*(b_felog - b_log);
haus_stat1;
"Probability of Chi-Square Statistic";
"being greater than this value with df:" k;
stat = cdfchic(haus_stat1,k);
stat;
print;
"Hausman Test between pooled logit (with country dummies) and FE logit:";
haus_stat2 = (b_felog - b_logc)'inv(cv_felog - cv_logc)*(b_felog - b_logc);
haus_stat2;
"Probability of Chi-Square Statistic";
"being greater than this value with df:" k;
stat = cdfchic(haus_stat2,k);
stat;
end;