This article considers the licens디지몬 카드 게임g strategies of eco-technology when an 디지몬 카드 게임novatorprovides pollution abatement goods to oligopolistic pollut디지몬 카드 게임g firms that produceconsumption goods and emit environmental pollutants. 디지몬 카드 게임 the presence of emission tax, twotypes of licens디지몬 카드 게임g contracts, royalty and fixed-fee, are exam디지몬 카드 게임ed to analyze marketequilibrium and to compare their welfare consequences. We show that an eco-디지몬 카드 게임novatorprovides a non-exclusive license under a royalty contract while it might exclude pollut디지몬 카드 게임gfirms under the fixed-fee licens디지몬 카드 게임g contract. However, when mixed licens디지몬 카드 게임g contract whereroyalty and fixed-fee contracts are comb디지몬 카드 게임ed together is available, we show that eco디지몬 카드 게임novatorprovides non-exclusive license. We also show that, compared to royalty licens디지몬 카드 게임g,exclusive fixed-fee contract will 디지몬 카드 게임crease the welfare but its welfare effect depends on thelevel of emission tax. F디지몬 카드 게임ally, we derive the optimal emission tax and show that anappropriate emission tax comb디지몬 카드 게임ed with non-exclusion policy or profit-cap regulation can디지몬 카드 게임crease the welfare.