How do intellectual property demonstration cities contribute to low-carbon development? Evidence from China

An intellectual property demonstration city (IPDC) not only promotes innovation, but also brings many unexpected gains, the most prominent of which is carbon reduction. Unfortunately, few scholars have included IPDC and carbon emissions in a unified research framework, ignoring the role of intellectual property protection in environmental governance. Therefore, this paper investigates the impact of IPDC on carbon emissions through a multi-period difference-in-difference (DID) model, a spatial DID model, and a mediating effect model with IPDC policy as a quasi-natural experiment. The research results are as follows: (1) IPDC policy has a significant inhibitory effect on carbon emissions. Compared to non-pilot cities, IPDC policy can reduce carbon emissions by about 20.6%. (2) There are temporal and regional heterogeneity of the IPDC policy on carbon emissions. More specifically, the carbon reduction effect of IPDC is more effective in large cities and cities with richer human capital, stricter environmental regulation, and higher financial development. Meanwhile, the policy effects in 2012 and 2015 are larger than those in 2018, while the policy effects in 2014, 2016, and 2019 are not significant. (3) IPDC policy reduces carbon emissions mainly by stimulating innovation and green innovation, and promoting R&D element agglomeration. (4) IPDC policy has obvious spatial spillover effects and leads to the surrounding cities becoming pollution havens. The above conclusions have implications for designing a better urbanization model to promote innovative development and reduce carbon emissions.