Abstract:     China′s new energy vehicles have achieved rapid development in recent years relying on the fiscal and tax "subsidy" policies such as "purchase subsidies" and "tax deductions". Excessive fiscal and tax "subsidy" policies have promoted the rapid development of China ′s new energy vehicle industry in the short term, but have also strengthened the "subsidy dependency" of new energy vehicles, inducing large-scale cheating behaviors. It is easy to cause controversy over the "fairness" of international trade. To this end, China has gradually implemented "subsidy declining "plan for new energy vehicles since 2016, and all subsidy policies will be withdrawn by 2020. In the context of China′s new energy vehicle "subsidy" policy gradually "downhill", effectively playing the role of "non-subsidized" policy is very important for the sustainable development of the new energy vehicle industry." Right of way priority y" as an "incentive mechanism" that encourages the environmental protection attributes of new energy vehicles to bring about a reduction in social marginal costs. By giving new energy vehicles the priority of listing or exercising right, the utility level of consumers of new energy vehicles is improved. The implementation of the "Charging guarantee" policy is conducive to reducing the variable costs in the use of new energy vehicles, stimulating and inducing consumers to consume new energy vehicles, and providing important basic guarantees for the development of the new energy vehicle industry. There are some differences in the effect of the "non-subsidized" policy on the time and regional dimensions. 
    Judging from the existing research literature, since China′s new energy vehicle industry policy is mainly based on "subsidy" policies, there is more research in the existing literature on the role of new energy vehicles "subsidy" policies. There are few studies on the role of "non-subsidized" policies; in addition, there are large differences in "transport bearing pressure" in different cities in China. The existing literature on the differences in the role of new energy vehicle policies in different regions lacks sufficient attention; There are some differences in the effect of time on the dimension of the effect, and the existing literature does not pay enough attention to the difference in the effect of the effect of new energy vehicle policies on the dimension of time. To make up for the lack of existing research, this research is based on a comparative perspective of the role of "non-subsidized" policies of "Right of way priority" and "Charging guarantee", taking China ′s new energy vehicle demonstration and promotion pilot cities as an example. The two-dimensional study analyzes the differences in the role of "non-subsidized" policies of "Right of way priority" and "Charging guarantee", with a view to providing decision-making references for the optimization of new energy vehicles′ "non-subsidized" policies.
    The study results show that: (1) The promotion effect of the "non-subsidized" policy is slightly lower than that of the "subsidized" policy, but the promotion effect is very significant. The implementation effect of the "non-subsidized" policy has been increasing year after year after the "subsidy decline " of new energy vehicles, and it has become increasingly prominent in inducing consumers in the passenger car market. As the "subsidized" policy of new energy vehicles "gradually declines", consumers will gradually reduce their dependence on "subsidized" policies such as "purchase subsidies" and "tax deductions" for new energy vehicles, and focus more on the use process. Convenience and practicality brought by the " Right of way priority " and "Charging guarantee" policies. (2) In the "non-subsidized" policy, the "Charging guarantee" policy has a stronger promotion effect than the " Right of way priority " policy, but the role of the " Right of way priority " policy has a relatively greater increase. After the implementation of the "subsidy decline policy", the growth rate of the "right of way priority policy" is significantly higher than that of the "charging guarantee policy". Although consumers are generally concerned about the "Charging guarantee", urban transportation bearing pressure will increase, and the "Right of way priority" of new energy vehicles will surely become the focus of more consumers. (3) There are obvious regional differences in the role of the "Right of way priority" policy. The higher the pressure on traffic load, the stronger the promotion of the "Right of way priority" policy. The "Charging guarantee" policy has promoted the promotion of the new energy vehicle market in cities with different traffic bearing pressures, but there are no obvious regional differences.
    This study has three implications for the optimization and adjustment of China′s new energy vehicle promotion policies: (1) With the gradual reduction of fiscal and tax subsidies, the government should strengthen the implementation of "non-subsidized" policy such as "right of way priority" and "Charging guarantee". "Strategic implementation of policies and improvement of relevant implementation details to actively cooperate with the implementation of "subsidy subsidies" for new energy vehicles to prevent the promotion and application of new energy vehicles from entering a "dark moment". (2) While rapidly advancing the layout of infrastructure such as charging piles, more attention should be paid to increasing the implementation of the "Right of way priority" policy for new energy vehicles, and a schedule to stop the production and sales of traditional vehicles should be issued in advance. So that more consumers are guided to purchase and use new energy vehicles, under the current situation of "subsidy decline". (3) The implementation of the "non-subsidized" policy should consider the differences in transportation resources in different cities, and implement the "non-subsidized" policy in accordance with local conditions. On the one hand, we must pay attention to the implementation of the "Right of way priority" policy, enhance the comparative advantages of new energy vehicle consumption and further release the role of the policy; on the other hand, adjust according to the actual implementation of the current "Charging guarantee" policy to improve new energy vehicle consumption environment to provide strong support for the popularity of new energy vehicles in the passenger car market in the future.

Key words: new energy vehicle (NEV), "non-subsidized" policy, right of way priority, charging guarantee, difference-in-difference model (DID)