Owing to its network spillover effect, information infrastructure performs outstandingly in promoting economic growth and technological innovation, and has received widespread attention. However, the ecological performance of information infrastructure, especially its impact on greenhouse gas (GHG) emission performance, has been studied less. To investigate this issue, using panel data for 281 prefecture-level cities in China from 2003 to 2018, we treat the Broadband China policy as a quasi-natural experiment in information infrastructure and conduct a time-varying difference-in-differences (DID) analysis. The results show that: (1) Information infrastructure significantly improves urban GHG emission performance. This conclusion holds even after excluding pilot selection endogeneity, sampling bias, and other policy interferences. (2) Technological innovation, industrial structural upgrading, factor allocation improvement, and tertiary agglomeration are effective channels by which information infrastructure improves GHG emission performance. (3) The treatment effect varies by city size, digital economy level, and economic status. Specifically, information infrastructure exhibits significant emission reduction performance in cities with large size, advanced digital economy, and leading economic status, while this effect drops in other cities. This study provides insights into the infrastructure transition to a carbon-neutral manner in China and other developing countries.
 

information infrastructure, greenhouse gas emission performance, broadband China policy, time-varying difference-in-differences, transmission mechanism, heterogeneity