All cit izens with valuat ions at least us+, + +)purchase the product, so the external is(1-8+)+X(s+, +)=(1-8+)+N(1-2s. ). Regulation directly reduces the emissions and also reduces demand which furt her reduces emissions. The ext ernality is stronger the more compet itive is the indust ry and weaker the more consumers int ernalize Since the externality is a pure public bad, every citizen incurs the harm. Consequent ly the utility U,(s+, +; u) of a cit izen with vff s+, ++)is U1(s+,+;)=(1-s+)-f{s+,+)-(1-s+)+x(s+,+)-(1-s+)+(aN-1) 1-0+)(=n+1)+n+1-s+)+aN-(1-s+)+aN-1) S,→ )(1-s+)+N The utility Uo(s+, t; u) of a citizen who does not purchase U The news media has an opport unity through the report it present s about -to ae ect private and public polit ics. Private politics pert ains to the consumption decisions of cit izen, and public polit ics corresponds to the collective choice of the regulation. Or influence of the news media on private politics is to ae ect demand for the produc considered in Section x, the media might also be able to ae ect demand through moral suasion. The influence on public polit ics is through the portion of the public that supports regulat lon C. Collective Choice Public polit ics governs the choice of t he regulation, where the st at us quo is no regula- tion(s+=0). Pivot al polit ics theory(Krehbiel(1998)(1999 )) predicts that a change in the stat us quo can require a supermajority to overcome a filibust er in the Senate or override a presidential veto. A supermajority may also be required to overcome vote buying(grose- se and Snyder(1996)). The relation bet ween cit izen preferences and the supermajority required to change the st at us quo is not known, however, so inst ead of modeling the in stit ut ions, the supermajority y of the public required for regulat ion to be enact ed will be taken as a paramet er where 122. Each cit izen is assumed to act as if she is pivot al.All citizens with valuations at least v∗(s+, θ+) purchase the product, so the externality is (1 − s+)θ+X(s+, θ+) = (1 − s+)θ+N(1 − v∗(s+,θ+) vˆ ). Regulation directly reduces the emissions and also reduces demand which further reduces emissions. The externality is stronger the more competitive is the industry and weaker the more consumers internalize it. Since the externality is a pure public bad, every citizen incurs the harm. Consequently, the utility U1(s+, θ+; v) of a citizen with v≥v∗(s+, θ+) is U1(s+, θ+; v) = v(1 − αs+) − y∗(s+, θ+) − (1 − s+)θ+X(s+, θ+) − (1 − s+)θ+(ηN − 1) = (1 − αs+) ￾ v − vˆ n + 1
+ 1 n + 1(1 − s+)θ+ηN − (1 − s+)θ+(ηN − 1) − ￾ 1 − v∗(s+, θ+) vˆ
(1 − s+)θ+N. (6) The utility U0(s+, θ+; v) of a citizen who does not purchase is U0(s+, θ+; v) = −(1 − s+)θ+X(s+, θ+). (7) The news media has an opportunity through the report it presents about θ to affect both private and public politics. Private politics pertains to the consumption decisions of citizens, and public politics corresponds to the collective choice of the regulation. One influence of the news media on private politics is to affect demand for the product. As considered in Section X, the media might also be able to affect demand through moral suasion. The influence on public politics is through the portion of the public that supports regulation. C. Collective Choice Public politics governs the choice of the regulation, where the status quo is no regula￾tion (s+ = 0). Pivotal politics theory (Krehbiel (1998)(1999)) predicts that a change in the status quo can require a supermajority to overcome a filibuster in the Senate or override a presidential veto. A supermajority may also be required to overcome vote buying (Grose￾close and Snyder (1996)). The relation between citizen preferences and the supermajority required to change the status quo is not known, however, so instead of modeling the in￾stitutions, the supermajority γ of the public required for regulation to be enacted will be taken as a parameter where γ≥ 1 2 . Each citizen is assumed to act as if she is pivotal. 14