Can informal environmental regulation restrain air pollution?-Evidence from media environmental coverage

In the Internet era, media environmental coverage has emerged as a critical mechanism of external supervision and governance, playing a pivotal role in local environmental governance. While previous research has predominantly focused on the role of media coverage in corporate governance, there remains a significant gap in exploring its impact on pollution control and its mechanisms from the perspective of informal environmental regulation (IER). This study addresses that gap by employing a panel regression model using data from Chinese prefecture-level cities between 2005 and 2023. The findings reveal that IER positively influences air pollution reduction by reinforcing environmental regulation enforcement (ERE) and increasing environmental accountability (EA) pressure. Further research uncovers that in areas with higher Internet penetration, the effectiveness of IER is amplified, leading to a "megaphone effect" that accelerates the spatial diffusion of media environmental coverages. Therefore, it is essential to establish an environmental information disclosure system, enhance the involvement of third-party such as the media in environmental decision-making, develop a scientific and reasonable environmental performance assessment system, and establish a governance framework involving collaboration among the government, enterprises, and the media for environmental preservation.