Green investment choice in a duopoly market with quality competition

Motivated by the fact that green investment and quality investment have become two vital long-term strategic tools for firms to improve their reputations and market competitiveness, this paper develops a game-theoretical model to study green investment choice decisions of two horizontally differentiated firms in the presence of quality competition. Given that the firms’ optimal green investment decisions do not always align with the environmental optimal objective, we further examine the motivation of government subsidy for green investment and the optimal subsidy programs. Three main findings are highlighted as follows. First, the internal relationship between green investment and quality investment plays a key role in firms’ green investment choices. Specifically, when green investment and quality investment are substitutes, no firm decides to make green investments, whereas when green investment and quality investment are complements, whether a firm makes a green investment depends on the green investment efficiency. Interestingly, with a moderate high green investment efficiency, the two ex-ante symmetric firms implement different technology investment strategies. Second, although green investment always benefits to curb total carbon emissions, a firm switching to green technologies does not always reduce its own emissions. Third, through different subsidy programs, the government can encourage firms to make green investments. When the subsidy is sufficiently high, the two firms can achieve a win-win outcome through green investments.