/********************************************************************* Scott Ashworth Josh Clinton Princeton University July 2006 Code for "Does Advertising Affect Turnout?" National Sample *********************************************************************/ /* Get Data */ use "NationalData",replace compress log using "Table1", replace text /********************/ /* Table 1 Results */ /********************/ tabstat vote_2 if advrt==0 /* Number in text */ tabstat vote_2 if advrt==1 /* Number in text */ tabstat vote_2 advrt if bg==1 /* Battleground Turnout and Exposure */ tabstat vote_2 advrt if bg==0 /* Non-Battleground Turnout and Exposure */ table bg log close log using "Table2", replace text /******************************************/ /* Table 2 Results */ /* National Sample Wald Estimator */ /******************************************/ /* Number in Table is the coefficient for advrt */ /* OLS */ reg vote_2 advrt, robust /* Full Sample -- Predicted Prob in text based on this */ reg vote_2 advrt if vote_1==0, robust /* "Non-voter" sample */ reg vote_2 advrt if vote_1==1, robust /* "Voter" sample */ gen iadvrt=vote_1*advrt /* Difference noted in text */ reg vote_2 advrt iadvrt vote_1, robust /* Wald Estimator */ ivreg vote_2 (advrt=bg), robust ivreg vote_2 (advrt=bg) if vote_1==0, robust ivreg vote_2 (advrt=bg) if vote_1==1, robust /* Calculate Hausman Tests for Each */ regress advrt bg /* Full Sample - F-stat in text from this*/ predict res, resid regress vote_2 advrt res test res /* Hausman Test */ regress advrt bg if vote_1==0 /* "Non-Voters" */ predict res1, resid regress vote_2 advrt res1 if vote_1==0 test res1 /* Hausman Test */ regress advrt bg if vote_1==1 /* "Voters" */ predict res2, resid regress vote_2 advrt res2 if vote_1==1 test res2 /* Hausman Test */ log close drop res res1 res2 log using "Table3", replace text /******************************************************************/ /* National Sample Characteristics by Battleground Status */ /* Table 3 */ /******************************************************************/ sum if bg==0 sum if bg==1 /* Conduct T-tests for sample differences */ ttest vote_1, by(bg) unequal /* Pre-Campaign Vote Intention */ ttest vote_2, by(bg) unequal /* Post-Campaign Vote Intention */ ttest advrt, by(bg) unequal /* Advertising Exposure Indicator*/ ttest pl_ntrst, by(bg) unequal /* Political Interest */ ttest strngth_, by(bg) unequal /* Strength of PID */ ttest age, by(bg) unequal /* Age */ ttest female, by(bg) unequal /* Female Indicator */ ttest hispanic, by(bg) unequal /* Hispanic Indicator */ ttest black, by(bg) unequal /* Balck Indicator */ ttest union, by(bg) unequal /* Union Indicator */ ttest church, by(bg) unequal /* Church Indicator */ ttest sen, by(bg) unequal /* Senate Race Indicator */ ttest gub, by(bg) unequal /* Gubernatorial Race Indicator */ log close /* ROBUSTNESS CHECK: Use vote measure indicating if "Definately will vote" */ ttest bvote_1, by(bg) unequal /* Pre-Campaign Vote Intention */ ttest bvote_2, by(bg) unequal /* Post-Campaign Vote Intention */ log using "Table4", replace text /******************************************************************/ /* Estimates of the Effect of Advertising on Turnout */ /* Table 4 */ /******************************************************************/ /* Number in Table is the coefficient for advrt */ /* OLS Results */ /* Table 4 column 1 */ reg vote_2 advrt black hispanic female strngth_ pl_ntrst age union church sen gub vote_1, robust /* Full Sample */ reg vote_2 advrt black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 0, robust /* Non-Voters -- Appendix Table 1*/ reg vote_2 advrt black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 1, robust /* Voters -- Appendix Table 1 */ /* Probit Results (Full Results Appendix Table 3) */ probit vote_2 black hispanic female strngth_ pl_ntrst age union church sen gub advrt vote_1, robust probit vote_2 black hispanic female strngth_ pl_ntrst age union church sen gub advrt if vote_1 == 0, robust probit vote_2 black hispanic female strngth_ pl_ntrst age union church sen gub advrt if vote_1 == 1, robust /* Get Average Effects (Table 4 -- column 2) From Bill Evans Code: http://www.bsos.umd.edu/econ/evans/econ626.htm Estimating the average treatment effect for the treated (people with advrt=1 already) Table 4 column 2 */ /* Full Sample */ use "NationalData",replace probit vote_2 advrt black hispanic female strngth_ pl_ntrst age union church sen gub vote_1 gen ones=1 matrix cov=e(V) matrix beta=e(b) drop if advrt==0 predict cdf1, p predict z1, xb gen pdf1=normd(z1) matrix vecaccum sum1= pdf1 advrt black hispanic female strngth_ pl_ntrst age union church sen gub vote_1 [iw=1/_N] recode advrt 1=0 predict cdf0, p predict z0, xb gen pdf0=normd(z0) matrix vecaccum sum0= pdf0 advrt black hispanic female strngth_ pl_ntrst age union church sen gub vote_1 [iw=1/_N] matrix g=sum1-sum0 gen delta_i=cdf1-cdf0 matrix vecaccum delta= ones delta_i [iw=1/_N], noc matrix cov_del=g*cov*g' matrix se_del=sqrt(cov_del[1,1]) matrix list delta /* Full Sample ATE Estimate */ matrix list se_del /* Full Sample ATE Stnd. Err. */ /* Initial non-voters */ use "NationalData",replace drop if vote_1 ==1 probit vote_2 advrt black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 0 gen ones=1 matrix cov=e(V) matrix beta=e(b) drop if advrt==0 predict cdf1, p predict z1, xb gen pdf1=normd(z1) matrix vecaccum sum1= pdf1 advrt black hispanic female strngth_ pl_ntrst age union church sen gub [iw=1/_N] recode advrt 1=0 predict cdf0, p predict z0, xb gen pdf0=normd(z0) matrix vecaccum sum0= pdf0 advrt black hispanic female strngth_ pl_ntrst age union church sen gub [iw=1/_N] matrix g=sum1-sum0 gen delta_i=cdf1-cdf0 matrix vecaccum delta= ones delta_i [iw=1/_N], noc matrix cov_del=g*cov*g' matrix se_del=sqrt(cov_del[1,1]) matrix list delta /* Non-Voter ATE Estimate */ matrix list se_del /* Non-Voter ATE Stnd. Err. */ /* Initial voters */ use "NationalData",replace drop if vote_1 ==0 probit vote_2 advrt black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 1 gen ones=1 matrix cov=e(V) matrix beta=e(b) drop if advrt==0 predict cdf1, p predict z1, xb gen pdf1=normd(z1) matrix vecaccum sum1= pdf1 advrt black hispanic female strngth_ pl_ntrst age union church sen gub [iw=1/_N] recode advrt 1=0 predict cdf0, p predict z0, xb gen pdf0=normd(z0) matrix vecaccum sum0= pdf0 advrt black hispanic female strngth_ pl_ntrst age union church sen gub [iw=1/_N] matrix g=sum1-sum0 gen delta_i=cdf1-cdf0 matrix vecaccum delta= ones delta_i [iw=1/_N], noc matrix cov_del=g*cov*g' matrix se_del=sqrt(cov_del[1,1]) matrix list delta /* Non-Voter ATE Estimate */ matrix list se_del /* Non-Voter ATE Stnd. Err. */ use "NationalData",replace */ Wald Estimates */ */ Table 4, column 3 */ ivreg vote_2 (advrt= bg), robust /* Full Sample */ ivreg vote_2 (advrt= bg) if vote_1==0, robust /* Non-Voters */ ivreg vote_2 (advrt= bg) if vote_1==1, robust /* Voters */ */ 2SLS */ */ Table 4, column 4 */ */ Full Results -- Appendix Table 1 */ ivreg vote_2 black hispanic female strngth_ pl_ntrst age union church sen gub vote_1 (advrt = bg), robust /* Full Sample */ ivreg vote_2 black hispanic female strngth_ pl_ntrst age union church sen gub (advrt = bg) if vote_1 == 0, robust /* Non-Voters */ ivreg vote_2 black hispanic female strngth_ pl_ntrst age union church sen gub (advrt = bg) if vote_1 == 1, robust /* Voters */ */ Hausman Test for 2SLS discussed in Text*/ regress advrt bg black hispanic female strngth_ pl_ntrst age union church sen gub vote_1 /* Full Sample */ predict res3, resid regress vote_2 advrt res3 black hispanic female strngth_ pl_ntrst age union church sen gub vote_1, robust /* Hausman test is the coefficient on res3 */ /* p = .029 */ /* Initial Non-Voters */ regress advrt bg black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 0 /* Appendix -- Table 2 */ predict res4, resid regress vote_2 advrt res4 black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 0, robust /* Hausman test is the coefficient on res4 */ /* p = .212 */ /* Initial Voters */ regress advrt bg black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 1 /* Appendix -- Table 2 */ predict res5, resid regress vote_2 advrt res5 black hispanic female strngth_ pl_ntrst age union church sen gub if vote_1 == 1, robust /* Hausman test is the coefficient on res5 */ /* p = .107 */ log close /* Bivariate Probit Code Results see: NatBiProbit.do */ */ Statistics for offsetting effects discussion in text */ */ Section 3.2 */ table vote_1 vote_2 if bg==0 table vote_1 vote_2 if bg==1 gen cng = vote_1 - vote_2 recode cng (-1=1) ttest cng, by(bg) unequal