Scaling Green Innovation Without Expanding the Bubble: How CSR Practices, Supply Chain Digitization, and Green Policies Shape Innovation Quality

The rapid growth of green patent applications has raised concerns about a quantity–quality paradox in green innovation: rising patent application volumes do not necessarily translate into genuine technological progress or environmental value. Instead, they may create a green innovation bubble in which applications remain ungranted, consume organizational resources, and fail to generate technological value. While prior research has explored corporate social responsibility (CSR), digital transformation and environmental policies separately, few studies have incorporated them into a unified framework to investigate their joint impacts on green innovation. To address this gap, this study constructs an integrated analytical framework on three CSR dimensions (environmental investment, employee rest protection, and charitable donations) alongside supply chain digitization and institutional policy support. Drawing on stakeholder theory and the resource-based view. Using 11,288 firm-year observations from 1411 Chinese A-share-listed manufacturing firms during 2016–2023, we estimate two-way fixed-effects models and conduct robustness, propensity-score-matching, and heterogeneity analyses. Environmental investment and supply chain digitization increase green patent output but also widen the application–grant gap, whereas weak employee rest protection reduces innovation output and charitable donations are negatively associated with both outcomes. CSR interactions reveal conditional complementarity and resource competition. At the functional level, planning digitization raises output while reducing the imbalance, and production digitization also improves conversion quality. Ecological compensation and green finance jointly help redirect resources toward substantive innovation. The findings show that scaling green innovation requires coordinated environmental, human-capital, digital, and institutional resources rather than quantity-oriented expansion, providing an integrated sustainable environmental management pathway relevant to SDGs 8, 9, 12, and 13.