The effects of transportation structural adjustment policy on carbon emission: Evidence from China

Abstract

Optimizing transportation structure is a pivotal measure to control pollution within the transportation industry. Previous studies showcased the carbon emission reduction potential of transportation structural adjustment, scant attention is devoted to the ex-post effects of transportation structural adjustment (TSA) policy. Evaluating the ex-post effectiveness of the TSA policy can elucidate the actual effects of the policy and offer valuable recommendations for future corrective measures. We utilize the difference-in-difference (DID) models to evaluate the causal effects of the TSA policy on carbon emission intensity in 31 Chinese provinces. We further construct spatial models to scrutinize the cross-regional impacts of the TSA policy to explain why some studies exist contradicting attitudes toward the effects of transportation environmental policies. Our findings indicate that the TSA policy indeed lowers the carbon emission intensity. It elevates the carbon emission intensity of neighboring areas, noticeable in regions not designated as priority development provinces. The supply and demand of road transportation influence the policy's effect. The policy diminishes road infrastructure and enhances rail infrastructure to curb carbon emission intensity. The policy's efficacy in carbon emission reduction is more pronounced in regions with higher highway traffic and congestion. Lastly, we offer recommendations to refine the subsequent policy, including regular evaluations, real-time monitoring in non-priority provinces, and reasonable investment planning.