Fostering Firm Collaborative Innovation: The Synergistic Role of Innovative City and Big Data Comprehensive Experimental Areas Policies

While the Chinese government implements the innovative city pilot (ICP) and big data comprehensive experimental areas (BDCEA) to foster collaborative innovation (CI), empirical research on their separate and synergistic effects on CI remains scant. This study constructs a dual-pilot quasi-natural experiment based on the spatiotemporal overlap of ICP and BDCEA to examine how their synergy promotes CI. Using data from Chinese listed firms, the main results reveal that the dual-pilot policy generates a synergistic enhancement of firm-level CI that exceeds the effect of either policy alone. This finding remains robust to tests of heterogeneous treatment effects and double machine learning. Moreover, this positive effect is particularly pronounced in non‑state‑owned firms, high‑tech industries, and firms located in Eastern China. Regarding collaboration patterns, dual-pilot policy promotes both intra- and inter-provincial CI and strengthens ties within dual-pilot cities and between dual-pilot and non-dual-pilot cities. Furthermore, mechanism analysis reveals that dual-pilot policy functions by alleviating financing constraints, reducing transaction costs, and fostering knowledge spillovers. This study extends the literature on cross-domain policy interactions and offers targeted policy recommendations for promoting CI more effectively.