When big data meets green finance: how cross-domain policy coordination promotes green collaborative innovation in Chinese cities

Using panel data for 272 Chinese cities from 2010 to 2022, this study employs the regression control method combined with Lasso and a Lasso-based synthetic control method to estimate the effect of the joint implementation of the National Big Data Comprehensive Pilot Zones (NBDCPZ) and the Green Finance Reform and Innovation Pilot Zones (GFRIPZ) on intercity green collaborative innovation (GCI), with Guangzhou as the treated city. Baseline estimates show that cross-domain policy coordination (CDPC) promotes Guangzhou’s intercity GCI. The finding is robust to placebo tests and alternative estimators, donor pools, covariate sets, outcome measures, sample periods, and estimation frameworks and is further supported by an alternative treated-city analysis using Guiyang. Mechanism analysis indicates that CDPC promotes intercity GCI by improving access to finance and fostering computing infrastructure development. The CDPC effect exceeds either standalone-policy benchmark under both estimators, while sequencing analysis shows an additional positive effect from adding GFRIPZ after NBDCPZ. The findings support closer coordination between digital-development and green-finance policies to strengthen intercity GCI.