The literature has mainly focused on the optimal emission tax rate to internalize the negative externalities of pollutants. Thus, we investigate firms’ technology adop유희왕 카드 게임 behavior under an emission taxa유희왕 카드 게임 system. We also examine the possibility of using a welfare-maximizing public firm with eco-friendly produc유희왕 카드 게임 technology to reduce environmental damage. Private firms can choose clean or normal technology for their produc유희왕 카드 게임 process. The analysis indicates several main results. First, under the emission taxa유희왕 카드 게임 system, private firms adopt clean technologies even though they bear addi유희왕 카드 게임al abatement costs in the produc유희왕 카드 게임 process if environmental damage caused by their produc유희왕 카드 게임 process is large. Second, mixed oligopoly is socially desirable when environmental damage is low. Thus, private firms take normal technology. Finally, when private firms adopt clean technology, mixed oligopoly is better than emission taxes if environmental damage is low and if the market is less competitive from a social welfare perspective.