Available on Request

Available on Request Models with Volume and Proportion Included Separately

Table 3: Tests of the Effects of Negative Advertising on Information about the Candidates

Ability to place pres. candidates ideologicallyb Certainty of candidates’ ideologyd

Logged volume of exposure to negative ads .028 (.016)# -.004 (.012) Proportion of negative ads to which exposed .002 (.001) -.002 (.001) Total spots in market -.028 (.046) .002 (.039) .033 (.033) .031 (.028) Local news viewing -.008 (.014) -.004 (.013) .011 (.011) .013 (.010) Newspaper reading .000 (.011) .000 (.011) .006 (.009) .006 (.009) Age -.007 (.002)** -.007 (.002)** -.001 (.001) -.001 (.001) African-American .092 (.092) .086 (.091) -.027 (.056) -.025 (.057) Female -.209 (.059)** -.211 (.060)** -.069 (.044) -.064 (.044) Income .000 (.000)# .000 (.000)# .000 (.000) .000 (.000) Education .104 (.020)** .103 (.020)** .034 (.016)* .034 (.016)* Political information .273 (.019)** .273 (.019)** .094 (.014)** .094 (.014)** Strength of partisanship .494 (.077)** .496 (.075)** .161 (.043)** .160 (.043)** Mobilized .171 (.059)** .172 (.059)** .021 (.055) .015 (.056) House race competitive .081 (.155) .076(.115) .108 (.074) .098 (.076) Senate race competitive .035 (.085) .019 (.084) -.007 (.049) -.003 (.048) Presidential race competitive -.002 (.088) .044 (.090) .032 (.044) .040 (.046) Constant .583 (.422) .301 (.376) 1.246 (.287)** 1.259 (.254)**

N 1200 1200 1046 1045 Adjusted R2/ Pseudo R2 .36 .36 .14 .14

**p < .01 *p < .05 #p < .10 (two-tailed tests) Standard errors are clustered by media market (DMA) and state Cell entries are all OLS estimates a exposure measures estimated based on all ads to date of interview b exposure measures estimated based on presidential ads to date of interview c exposure measures based on all ads d exposure measures based on all presidential ads

1 Table 3: Tests of the Effects of Negative Advertising on Information about the Candidates (continued)

Bush/Gore likesb Bush/Gore dislikesb

Logged volume of exposure to negative ads .081 (.030)** .123 (.031)** Proportion of negative ads to which exposed .006 (.002)** .008 (.003)* Total spots in market -.099 (.082) -.014 (.083) .081 (.085) .218 (.081)** Local news viewing .026 (.028) .038 (.025) -.019 (.023) -.000 (.022) Newspaper reading -.011 (.020) .012 (.020) .003 (.020) .002 (.021) Age .009 (.004)# .009 (.004)# -.006 (.003)* -.006 (.003)* African-American -.281 (.207) -.297 (.210) -.063 (.153) -.083 (.156) Female .236 (.119)# .230 (.124)# -.055 (.104) -.059 (.109) Income .000 (.000) .000 (.000) .000 (.000) .000 (.000) Education .172 (.037)** .169 (.037)** .188 (.037)** .183 (.037)** Political information .240 (.036)** .240 (.036)** .379 (.039)** .379 (.040)** Strength of partisanship .708 (.124)** .712 (.123)** .153 (.173) .162 (.173) Mobilized .275 (.113)* .277 (.112)** .282 (.114)* .282 (.112)* House race competitive -.191 (.167) -.206(.161) -.294 (.151)# -.330 (.154)* Senate race competitive -.065 (.141) -.113 (.135) -.245 (.133)# -.324 (.135)* Presidential race competitive .018 (.147) .151 (.148) -.309 (.130)* -.100 (.152) Constant .875 (.702) .059 (.724) .104 (.813) -1.214 (.733)

N 1200 1200 1200 1200 Adjusted R2/ Pseudo R2 .16 .16 .23 .23

**p < .01 *p < .05 #p < .10 (two-tailed tests) Standard errors are clustered by media market (DMA) and state Cell entries are all OLS estimates a exposure measures estimated based on all ads to date of interview b exposure measures estimated based on presidential ads to date of interview c exposure measures based on all ads d exposure measures based on all presidential ads

2 Table 4: Tests of the Effects of Negative Advertising on Attention to the Campaign, Perceptions of Government, and Voting

Attention Perceptions of closeness of Remember seeing an ada Attention to the campaigna pres. raceb

Logged volume of exposure to negative ads .233 (.043)** .027 (.012)* .125 (.053)* Proportion of negative ads to which exposed .012 (.005)* .000 (.001) .006 (.006) Total spots in market -.091 (.125) .218 (.110)* -.038 (.031) .007 (.023) -.133 (.152) .035 (.135) Local news viewing .158 (.036)** .234 (.036)** .032 (.008)** .042 (.007)** -.011 (.044) .033 (.038) Newspaper reading .026 (.034) .027 (.033) .018 (.008)* .019 (.008)* -.019 (.034) -.017 (.034) Age -.012 (.005)* -.013 (.005)* .004 (.002)* .004 (.002)* .008 (.007) .008 (.007) African-American -.051 (.259) .011 (.250) .200 (.068)** .208 (.066)** -.332 (.300) -.296 (.288) Female -.359 (.162)* -.252 (.162) .044 (.032) .055 (.032)# -.060 (.180) -.015 (.175) Income .000 (.000) .000 (.000) -.000 (.000) -.000 (.000) -.000 (.000) -.000 (.000) Education .080 (.061) .075 (.061) .047 (.014)** .046 (.015)** .242 (.069)** .242 (.069)** Political information -.067 (.040)# -.063 (.041) .125 (.012)** .125 (.012)** .205 (.072)** .203 (.073)** Strength of partisanship .346 (.254) .345 (.249) .283 (.057)** .285 (.057)** -.086 (.312) -.084 (.318) Mobilized .664 (.179)** .653 (.175)** .151 (.037)** .155 (.037)** .351 (.220) .355 (.220) House race competitive -.382 (.375) -.431 (.355) .014 (.064) .004 (.063) .140 (.304) .116 (.305) Senate race competitive .285 (.209) .344 (.197)# .011 (.040) .023 (.039) -.429 (.209)* -.381 (.187)# Presidential race competitive .494 (.204)* .535 (.201)** -.034 (.036) -.036 (.036) .535 (.208)* .551 (.213)* Constant 1.245 (1.231) 1.374 (.281)** 1.293 (.287) .859 (.206)** 1.493 (1.400) -.186 (1.198)

N 1198 1198 1200 1200 1180 1180 Adjusted R2/ Pseudo R2 .13 .11 .28 .28 .08 .07

**p < .01 *p < .05 #p < .10 (two-tailed tests) Standard errors are clustered by media market (DMA) and state. Cell entries are OLS (attention to the campaign, external efficacy, perceptions of govt. power) and logit (seeing an ad, closeness of pres. race, voted) a exposure measures estimated based on all ads to date of interview b exposure measures estimated based on presidential ads to date of interview c exposure measures based on all ads d exposure measures based on all presidential ads

3 Table 4: Tests of the Effects of Negative Advertising on Attention to the Campaign, Perceptions of Government, and Voting

Perceptions of government Turnout External efficacyc Perceptions of govt. powerb Votedc

Logged volume of exposure to negative ads -.013 (.017) -.023 (.011)* .128 (.051)* Proportion of negative ads to which exposed -.004 (.002)# -.003 (.002)* .020 (.008)* Total spots in market .024 (.051) .025 (.050) .044 (.032) .030 (.030) .045 (.141) .105 (.130) Local news viewing .005 (.015) .004 (.012) .007 (.010) -.000 (.008) -.069 (.047) -.032 (.040) Newspaper reading .001 (.009) .001 (.009) -.001 (.006) -.001 (.006) .064 (.031)* .064 (.031)* Age -.004 (.002)* -.004 (.002)* .001 (.001) .001 (.001) .010 (.005)* .011 (.005)* African-American -.006 (.107) -.002 (.107) -.177 (.062)** -.179 (.062)** .708 (.303)* .713 (.300)* Female -.077 (.054) -.075 (.055) -.053 (.040) -.057 (.041) .083 (.154) .102 (.151) Income .000 (.000) .000 (.000)# .000 (.000) .000 (.000) .000 (.000) .000 (.000) Education .165 (.024)** .164 (.024)** -.022 (.011)* -.021 (.021)# .349 (.056)** .348 (.057)** Political information .097 (.016)** .097 (.016)** .038 (.013)** .038 (.012)** .364 (.064)** .364 (.063)** Strength of partisanship .194 (.075)* .196 (.075)* -.028 (.053) -.028 (.053) .909 (.223)** .914 (.226)** Mobilized .261 (.055)** .263 (.054)** .099 (.034)** .099 (.034)** 1.282 (.189)** 1.280 (.188)** House race competitive .079 (.080) .076 (.080) .046 (.049) .049 (.052) -.318 (.210) -.329 (.197)# Senate race competitive -.019 (.074) -.012 (.073) -.132 (.048)** -.126 (.046)** -.233 (.187) -.255 (.189) Presidential race competitive .017 (.075) .014 (.074) .024 (.040) .021 (.039) .024 (.210) .044 (.220) Constant 1.600 (.477)** 1.589 (.447)** 1.928 (.285)** 2.069 (.265)** -3.221 (1.361)* -3.869 (1.259)**

N 1193 1193 1157 1157 1199 1199 Adjusted R2/ Pseudo R2 .22 .22 .06 .06 .26 .26

**p < .01 *p < .05 #p < .10 (two-tailed tests) Standard errors are clustered by media market (DMA) and state. Cell entries are OLS (attention to the campaign, external efficacy, perceptions of govt. power) and logit (seeing an ad, closeness of pres. race, voted) a exposure measures estimated based on all ads to date of interview b exposure measures estimated based on presidential ads to date of interview c exposure measures based on all ads d exposure measures based on all presidential ads

4 Three-Stage Least Squares Models Table 3: Tests of the Effects of Negative Advertising on Information about the Candidates

Ability to place pres. Certainty of candidates candidates’ Bush/Gore Bush/Gore ideologicallyb ideologyd likesb dislikesb

Logged volume of exposure to -.127 (.055)* -.002 (.005) .098 (.079) -.257 (.111)* negative ads Proportion of negative ads to .046 (.014)** .002 (.006) .009 (.021) .102 (.029)** which exposed Total spots in market .044 (.066) .035 (.032) -.122 (.104) .116 (.132) Newspaper reading -.002 (.011) .008 (.007) .014 (.019) .006 (.020) African-American .063 (.102) -.030 (.063) -.390 (.191)* -.123 (.197) Female -.202 (.065)** -.054 (.041) .271 (.119)* -.050 (.125) Political information .326 (.024)** .156 (.057)** .329 (.035)** .467 (.048)** Strength of partisanship .420 (.114)** -.209 (.059)** .795 (.162)** .085 (.232) Constant -.193 (.559) 1.353 (.302)** 1.869 (.904)** -.693 (1.113) Volume of Volume of Volume of Volume of Endogenous variable (1) exposure exposure exposure exposure Local news viewing .188 (.025)** .287 (.030)** .192 (.025)** .189 (.025)** Age -.001 (.004) .011 (.004)* .000 (.004) -.000 (.004) Income .000 (.000)* .000 (.000)# .000 (.000)* .000 (.000)* Education .002 (.041) -.054 (.048) -.010 (.041) -.004 (.041) Political information -.033 (.038) -.005 (.044) -.027 (.038) -.030 (.038) Strength of partisanship .236 (.169) .145 (.202) .230 (.169) .229 (.169) Mobilized .083 (.132) -.072 (.158) .048 (.143) .068 (.133) House race competitive -.204 (.191) -.344 (.226) -.263 (.193) -.247 (.192) Senate race competitive -.212 (.120)# -.279 (.141)* .205 (.121)# .192 (.120) Presidential race competitive 2.604 (.130)** 3.091 (.151)** 2.578 (.130)** 2.588 (.130)** Constant .386 (.262) .992 (.316) .406 (.263) .400 (.262) Proportion of Proportion of Proportion of Proportion of Endogenous variable (2) exposure exposure exposure exposure Local news viewing .618 (.234)** 1.586 (.256)** .751 (.289)** .612 (.227)** Age -.113 (.034)** -.002 (.039) -.070 (.042)# -.068 (.033)* Income .000 (.000)* .000 (.000)* .000 (.000)* .000 (.000)* Education 1.209 (.354)** .500 (.417) .203 (.467) 1.098 (.339)** Political information -.668 (.410) -.310 (.384) -.142 (.433) -.610 (.447) Strength of partisanship 2.281 (1.914) .241 (1.756) 2.123 (1.924) 1.829 (1.912) Mobilized 1.396 (1.160) -3.856 (1.368)** -1.001 (1.519) 1.203 (1.113) House race competitive -2. 331 (1.822) -6. 818 (1.952)** -5.079 (2.193)** -4.321 (1.777)* Senate race competitive .039 (1.150) .540 (1.220) .204 (1.374) -1.216 (1.118) Presidential race competitive 6.801 (1.399)** 10.785 (1.308)** 5.651 (1.481)** 6.091 (1.389)** Constant 7.357 (2.520)** 15.476 (2.734)** 10.562 (2.998)** 7.108 (2.458)**

N 1048 1203 1203 1203

**p < .01 *p < .05 #p < .10 (two-tailed tests) Standard errors are clustered by media market (DMA) and state

1 Table 4: Tests of the Effects of Negative Advertising on Attention to the Campaign

Perceptions of Remember Attention to the closeness of seeing an ada campaigna pres. raceb

Logged volume of exposure to negative ads .106 (.018)** .100 (.028)** .031 (.015)* Proportion of negative ads to which exposed -.003 (.004) -.001 (.006) -.010 (.004)** Total spots in market -.042 (.028) -.100 (.043)* -.009 (.023) Newspaper reading .003 (.005) .030 (.007)** .000 (.004) African-American -.023 (.040) .157 (.062)* -.053 (.033) Female -.061 (.026)* .055 (.040) .001 (.021) Political information .004 (.008) .154 (.012)** .028 (.006)** Strength of partisanship .047 (.036) .331 (.055)** .006 (.030) Constant .807 (.226)** 1.950 (.348)** .978 (.184)** Volume of Volume of Volume of Endogenous variable (1) exposure exposure exposure Local news viewing .393 (.027)** .393 (.027)** .389 (.027)** Age -.008 (.004)* -.005 (.004) -.008 (.004)# Income .000 (.000) .000 (.000) .000 (.000) Education .020 (.043) -.003 (.043) -.045 (.044) Political information -.069 (.041)# -.075 (.041)# -.055 (.041) Strength of partisanship .195 (.181) .164 (.181) .193 (.183) Mobilized .374 (.140)** .344 (.141)* .241 (.144)# House race competitive .102 (.202) .164 (.204) .154 (.207) Senate race competitive 1.716 (.128)** 1.721 (.129)** 1.732 (.131)** Presidential race competitive .754 (.139)** .704 (.139)** .723 (.141)** Constant 1.995 (.279)** 1.840 (.280)** 2.177 (.285)** Proportion of Proportion of Proportion of Endogenous variable (2) exposure exposure exposure Local news viewing 1.020 (.215)** 1.018 (.215)** .916 (.213)** Age -.024 (.031) -.013 (.031) -.041 (.029) Income .000 (.000)* .000 (.000)# .000 (.000)* Education -.518 (.349) -.372 (.347) -.904 (.326)** Political information -.287 (.323) -.373 (.323) -.008 (.317) Strength of partisanship .566 (1.437) .397 (1.434) .482 (1.428) Mobilized 2.320 (1.133)* 2.611 (1.126)* 1.133 (1.056) House race competitive -.118 (1.635) .002 (1.625) -.666 (1.517) Senate race competitive 7.806 (1.025)** 7.682 (1.021)** 7.880 (.989) Presidential race competitive -3.566 (1.105)** -3.756 (1.103)** -3.373 (1.080)** Constant 16.554 (2.236)** 15.587 (2.227)** 19.739 (2.140)**

N 1201 1203 1203

2 Table 4: Tests of the Effects of Negative Advertising on Perceptions of Government, and Voting

External Perceptions of efficacyc govt. powerb Votedc

Logged volume of exposure to negative ads .050 (.092) .098 (.053)# -.028 (.037) Proportion of negative ads to which exposed -.035 (.030) -.033 (.017)# .009 (.012) Total spots in market .070 (.048) .018 (.029) .012 (.019) Newspaper reading .004 (.010) .002 (.006) .014 (.004)** African-American -.053 (.096) -.205 (.058)** .077 (.040)# Female -.057 (.059) -.060 (.036)# .033 (.025) Political information .185 (.019)** .038 (.011)** .077 (.007)** Strength of partisanship .236 (.088)** .019 (.053) .179 (.035)** Constant 2.354 (.347)** 2.481 (.210)** .211 (.142) Volume of Volume of Volume of Endogenous variable (1) exposure exposure exposure Local news viewing .503 (.023)** .513 (.023)** .515 (.023)** Age .006 (.003)# .004 (.003) .005 (.003) Income .000 (.000) .000 (.000) .000 (.000) Education -.127 (.036)** -.057 (.038) -.065 (.037)# Political information -.019 (.034) -.048 (.035) -.054 (.034)# Strength of partisanship .317 (.153)* .272 (.158)# .306 (.152)* Mobilized .052 (.118) .099 (.122) .174 (.120) House race competitive .024 (.170) -.004 (.177) .040 (.174) Senate race competitive .946 (.108)** .995 (.111)** .979 (.109)** Presidential race competitive .559 (.115)** .548 (.118)** .560 (.117)** Constant 3.304 (.234)** 3.118 (.242)** 3.031 (.238)** Proportion of Proportion of Proportion of Endogenous variable (2) exposure exposure exposure Local news viewing 1.396 (.143)** 1.511 (.145)** 1.498 (.143)** Age .044 (.020)* .018 (.020) .028 (.021) Income .000 (.000)* .000 (.000) .000 (.000)* Education -.910 (.221)** -.223 (.227) -.280 (.232) Political information .181 (.213) -.127 (.216) -.173 (.215) Strength of partisanship 1.621 (.960)# 1.520 (.981) 1.656 (.955)# Mobilized -.242 (.715) .139 (.735) 1.126 (.753) House race competitive -.557 (1.036) -.706 (1.073) -.433 (1.086) Senate race competitive 4.772 (.675)** 5.412 (.687)** 4.925 (.682)** Presidential race competitive 1.112 (.705) 1.054 (.719) 1.107 (.734) Constant 19.915 (1.439)** 17.901 (1.478)** 16.983 (1.487)**

N 1196 1160 1202

3 Table 5: The Direct and Indirect Effects of Negative Advertising on Turnout

Logged exposure to negative advertising .058 (.113) Proportion of negative ads to which exposed .002 (.016) Total spots in market .164 (.145) Local news viewing -.103 (.067) Newspaper reading .051 (.040) Age .017 (.006)** African-American .819 (.357)* Female .353 (.176)* Income .000 (.000) Education .210 (.078)** Political information .243 (.085)** Strength of partisanship .426 (.324) Mobilized 1.222 (.233)** House race competitive -.505 (.249)* Senate race competitive -.314 (.221) Presidential race competitive .049 (.263) Remember seeing an ad .179 (.194) Perceptions of closeness of race .576 (.348)# Ability to place pres. candidates ideologically .186 (.117) External efficacy .314 (.118)** Perceptions of government power -.019 (.181) Certainty of candidates’ ideology .063 (.151) Attention to the campaign .581 (.129)** Bush/Gore likes -.046 (.064) Bush/Gore dislikes .073 (.068) Constant -6.319 (1.541)**

N 992 Pseduo R2 .30

**p < .01 *p < .05 #p < .10 (two-tailed tests) Standard errors are clustered by media market (DMA) and state.