The report of the 20th National Congress of the Communist Party of China pointed out that “high-quality development is the primary task of building a socialist modern country in an all-round way”, and made new important arrangements for promoting “quality power”. “Powerful brand” is the core connotation of high-quality development. “Powerful Quality” is a realistic path for China to promote a strong and resilient national economic cycle system and accelerate the construction of a new development pattern in the new era. However, the quantitative evaluation of the implementation effect of the national trademark brand strategy demonstration policy is still extremely scarce. Based on the large sample data of the trademark office of the state intellectual property office of China, this paper applies the quasi-natural experimental methods of DID and DDD to evaluate the impact of the national trademark strategy on the trademark registration behavior of enterprises. It is found that the implementation of the national trademark strategy significantly increases the number of trademark registrations in the experimental group. Furthermore, the dynamic marginal effect shows that the policy effect shows time lag and persistence. The above results remain robust after the effectiveness tests such as parallel trend test, controlling ex ante time trend and excluding expected effects, as well as the robustness tests such as counterfactual test, excluding other policy interference, adopting different matching methods and changing the clustering level of standard error. From the perspective of heterogeneity analysis, the policy effect of trademark brand strategy is significantly affected by the regional business environment, which is more obvious in the samples with high degree of regional marketization and low degree of resource mismatch. The mechanism test shows that the trademark brand strategy policy can promote the trademark brand construction by strengthening external promotion, strengthening intellectual property protection and promoting facilitation of trademark application. In the context of the “Brand China” strategy, this paper enriches the literature on the brand upgrading effect caused by the regional development planning with Chinese characteristics, and provides policy basis for promoting the transformation of “China Made” to “Chinese Brand”, leading the upgrading of the supply and demand structure, and accelerating the construction of a unified national market.

Circular economy policy can improve the environmental performance of enterprises by reducing resource consumption and waste and realizing resource recycling, but it may also frustrate the enthusiasm of enterprises to control pollution by increasing the pressure of regulation cost or being trapped by technical complexity. Therefore, this paper uses China’s industrial enterprise database, industrial enterprise pollution emission data and input-output data to identify the impact of circular economy pilot policies on corporate pollution emission by constructing a difference-in-differences model, so as to analyze whether it is a “booster” or a “stumbling block” in corporate pollution control. It is found that after the implementation of the circular economy pilot policy, the pollutant emissions of the experimental group are significantly lower than those of the control group, indicating that the circular economy pilot policy has significantly improved the environmental performance of enterprises. This conclusion is still valid after a series of robustness tests such as replacing the explained variable, deleting the contemporaneous policy interference, controlling the time trend of the industry, and randomly selecting the placebo in the experimental group. Furthermore, circular economy policies can promote enterprises’ environmental performance by promoting energy saving and consumption reduction, strengthening end treatment and enhancing technology development capabilities. The heterogeneity test finds that the effect of circular economy policy is more prominent in the samples of enterprises in non-resource-based cities, enterprises in super-large cities and enterprises with higher openness level to foreign investment in the upstream service industry. Under the “dual carbon” goal, the conclusions of this paper expand the theoretical research on the effect evaluation of environmental regulation policies from the new perspective of circular economy, and provide targeted policy basis for helping to achieve green, circular and low-carbon development, promoting the construction of ecological civilization, and planning a “beautiful China” blueprint.