This research is aimed to analyze the effectiveness of the government’s subsidy policies for consumers purchasing electric vehicles via the Stackelberg game approach, in which the government acts as leader and both electric vehicle manufacturer and automobile manufacturer act as followers. The government determines the subsidy amount for consumers purchasing electric vehicles first, and both firms determine their prices simultaneously after investigating the subsidy amount that the government announces. Moreover, our research considers behavioral theories into the models in order to describe consumer behaviors while making purchasing decisions in a plausible way. Finally, we investigate three proposed subsidy policies with respect to the demand of electric vehicles, the social welfare and the optimal subsidy amount. Our study shows that one-time subsidy policy performs the best in promoting the adoption of electric vehicles with the lowest costs.