Does China's low-carbon city pilots policy stimulate green development? Evidence from a multiple mediating effect model

Low-carbon city pilot (LCCP) policy is a progressive pollution regulation policy. Besides its role in carbon emission reduction, it has a profound impact on green growth performance and green innovation efficiency. Based on the data of 12 pilot cities and 14 non-pilot cities in the Yangtze River Delta (YRD), this study applies the PSM-DID and spatial mediating model to investigate the multi-dimensional policy effects of LCCP policy on green growth performance and green innovation efficiency. First, the direct effect of LCCP policy on green growth performance has reached 1.46%, ever since its implementation in 2017. Second, considering the intercity innovation cooperation in YRD, LCCP policy has influenced green innovation efficiency by an increase of 12.6%. Furthermore, the time-spatial DID model and multiple mediating effect model identify that LCCP policies have significantly improved green innovation cooperation. Such policies act on the industrial structure upgrading path to achieve the ultimate objective of carbon emission reduction and green growth performance. Third, the green innovation cooperation and substantial transformation of industrial structure upgrading played an important role in realizing the LCCP policy's effect, with its mediating effect reaching 33.63%.