Institutional Investors Preference for Supply-Chain Firms with High ESG Transparency and Frequent On-Chain Disclosure

Blockchain technology offers the potential for immutable, real-time Environmental-Social-Governance (ESG) data streams, yet robust causal evidence on their capital-market impact remains limited. Using 43,896 firm-quarter observations (2018-2024) across 1,829 Chinese A-share supply-chain firms, we develop an On-Chain Disclosure Intensity (ODI) index by parsing 9.4 million ESG-tagged smart-contract events from Ethereum-based decentralised autonomous organisations. Our identification strategy combines an instrumental-variables two-stage least squares (IV-2SLS) approach, leveraging DAO vote density and provincial blockchain-for-sustainability subsidies, with a staggered difference-in-differences design exploiting 2023-2024 disclosure mandates. A one-standard-deviation increase in instrumented ODI raises institutional ownership by 1.32 percentage points and reduces the weighted-average cost of capital by 38 basis points; treatment firms subject to policy shocks see an additional 6.05-point ownership gain. Robustness checks, including entropy-weighted TOPSIS scoring, placebo reforms, alternative clustering, and non-parametric randomisation, corroborate the transparency premium. The findings indicate that tamper-proof ESG data can complement conventional narrative reports, providing managers with a pathway to lower financing costs and offering regulators quantitative benchmarks for standardising blockchain-based disclosure.