China's supply chain digitalization reduces urban air pollutants and carbon emissions locally

This study constructs a balanced panel dataset of 279 prefecture-level cities in China from 2005 to 2021 to examine how supply-chain digitalization (SCD) influences urban pollution and carbon reduction (lnPCR). The main independent variable, SCD, is defined as the interaction between a time dummy (policy implementation period) and a policy dummy (pilot vs. non-pilot cities) under the 2018 Supply Chain Innovation and Application Pilot Policy (SCIAPP). The dependent variable, lnPCR, captures the combined effect of urban pollution and carbon emissions, measured as the interaction between an environmental pollution index and carbon emission levels. The control variables include urbanization level (Urban), population size (lnSize), urban economic density (lnEco), financial development level (Finance), fiscal decentralization (Fiscal), and degree of openness (Foreign), all reflecting socioeconomic and institutional characteristics of each city. The mechanism variables—green technological innovation (Green_pat), government innovation support (Inno_support), and energy consumption (lnenergy)—capture potential transmission pathways of SCD’s environmental effects. Data were drawn from national and provincial statistical yearbooks, CEADs, and government databases, ensuring consistency and comparability across cities and years.