Effects of smart city construction on energy saving and CO2 emission reduction: Evidence from China

Developing countries constantly face the predicament of how to achieve the common progress of economic growth and environmental protection, and smart city construction may be the key. This study takes a smart city pilot policy in China as the starting point, and systematically evaluates the effects of smart city construction on energy saving and CO2 emission reduction using a progressive difference-in-differences method. The research conclusions show that: 1. Smart city construction has significantly reduced per capita CO2 emissions, with a reduction effect of approximately 18.42 logarithmic percentage points. This conclusion remains valid in the placebo test, instrumental variable method, and a series of robustness verifications. 2. There is an inverted U-shaped relationship between energy efficiency and per capita CO2 emissions, and most cities in China have crossed the inflection point; smart city construction achieves energy savings and reduces per capita CO2 emissions by improving energy efficiency. 3. The effect of smart city construction on CO2 emission reduction is more obvious in cities with higher administrative levels, higher levels of neutral technological progress and green innovation, and higher levels of advanced industrial structure. This research provides an empirical basis for how developing countries or regions can move toward sustainable development through digital and intelligent transformation and demonstrates the importance of providing new infrastructure construction such as smart cities from the perspective of a low-carbon economy.