Impact of the dual pilot policy of Smart Cities and Broadband China strategy on air pollution reduction in China

Abstract The strategies of Smart Cities and Broadband China are pivotal policy arrangement for propelling the development of China's digital economy. Accurately assessing their synergistic impact on urban air pollution provides vital insights for flexibly deploying policy portfolios and advancing pilot programs. Drawing from panel data of 280 Chinese cities from 2009 to 2022, this study adopts a multi-period difference-in-differences approach to construct a quasi-natural experiment around the dual-pilot policies of Smart City and Broadband China and investigate their impact on urban air pollution. The results indicate that the dual pilot policy demonstrates a significant synergistic effect in mitigating urban air pollution. Compared with single pilot policies, the dual pilot policy’s synergistic air pollution reduction effect is more notable, thus realizing a “1 + 1 > 2” policy outcome. The air pollution reduction efficacy exhibits marked heterogeneity across cities with different geographical locations, resource endowments, environmental policy preferences, and city scales—with more pronounced impacts in eastern cities, non-resource-based cities, cities prioritizing environmental protection, and large cities. The intrinsic mechanism lies in promoting industrial structure upgrading and enhancing technological innovation.