Spatial spillover effects of manufacturing agglomeration on China's total factor carbon productivity: evidence from the regulatory role of fiscal decentralization.

Based on the theory of new economic geography, this paper used panel data from 284 cities in China from 2006 to 2019 to determine the effects of spatial spillover and heterogeneity of manufacturing agglomeration (MA) on urban total factor carbon productivity (TFCP) and the regulatory effect of fiscal decentralization on the outcome. The results showed that (1) MA shifted from the eastern region of China to the central and western regions, with the center of gravity moving towards the south. The spatial pattern of urban TFCP displayed the solidifying characteristics of "low-level agglomeration and high-level dispersion," with technological progress being the primary driver. (2) The MA had a significant U-shaped effect on the TFCP of local and nearby cities, promoting the improvement of urban TFCP through Jacobs' and Porter's externalities but not MAR externalities. (3) Regarding regional differences, MA had a significant U-shaped impact on urban TFCP in the eastern and central regions. At different levels of manufacturing development, there was an inverted U-shaped relationship in both manufacturing and non-manufacturing metropolitan areas. For varying degrees of manufacturing industry agglomeration, increasing the level of MA improved urban TFCP in low agglomeration areas, but inhibited it in high agglomeration areas. (4) The implementation of fiscal decentralization nationwide and in the eastern and central regions significantly weakened the impact of MA on TFCP. Furthermore, fiscal decentralization significantly enhanced the influence of MA on TFCP in cities exhibiting high levels of economic development, advanced industrial structure and strict environmental regulations. Therefore, based on the unique developmental characteristics of the manufacturing industry in various cities, fiscal policies ought to be tailored to local circumstances to support key areas. This strategy should facilitate the high-quality development of manufacturing industry and low-carbon development of cities.

Impact of low-carbon city pilot policies on urban green innovation from the perspective of spatial and temporal heterogeneity.

The low-carbon city pilot policy (LCPP) in China is an active response to climate change, with cities serving as the main agents of action. Enhancing green innovation at a city-wide level can effectively support the promotion of pilot cities' efforts towards sustainable growth. Using panel data from 204 prefectures collected from 2005 to 2019, we adopted the time-varying difference-in-differences (DID) model and the spatial Durbin model combined with time-varying DID (SDM-DID) to determine the impact of the LCPP on urban green innovation and its temporal and spatial heterogeneity. Empirical findings showed that (1) LCPP had a significant positive impact on urban green innovation, and green invention patents had a greater green innovation effect than green utility model patents. (2) Heterogeneity analysis revealed that in terms of geographical location, the pilot policy was more effective in promoting urban green innovation in the eastern and central regions in comparison to the western region. At the city level, the pilot policy had a greater impact on green innovation in first- and second-tier cities. With regard to city scale, large-scale cities showed a greater impact on green innovation than small- and medium-sized cities. (3) Mechanistic testing revealed that LCPPs stimulated urban green innovation by talent aggregation, increasing government support for innovation, and public participation; but the mechanism for alleviating financing constraints has yet to be effectively validated. (4) The LCPP showed a spatial spillover effect, whereby one city's low-carbon governance yielded institutional dividends for neighboring cities both geographically and economically, and the impact was more pronounced in those cities that were not resource-based. This study presents empirical evidence at the urban and spatial levels, supporting the comprehensive promotion of low-carbon city construction and development in China.