Liquidity and Market Microstructure of Tokenized Carbon Assets Trading in Blockchain-Based Voluntary Carbon Markets: A Mean-Centered MMRM with HAC Corrections

This study investigates how on-chain trading activity influences liquidity and market microstructure in blockchain-based voluntary carbon markets (VCMs) while accounting for the regulation index as a conditioning factor. Using mean-centered MMRM with HAC corrections on daily data for $KLIMA, BCT, and MCO2, the results indicate that liquidity is associated with distinct trading channels across tokens. Transaction value is positively associated with market depth, while fragmented trading intensity is associated with wider bid-ask spreads. Market expansion is further linked to higher price volatility, particularly in structurally thin markets. The regulation index predominantly acts as a homologizer moderator, reinforcing existing relationships rather than fundamentally altering their direction, with stronger conditioning effects observed in thinner markets. Overall, the findings suggest that liquidity in tokenized carbon markets is more closely associated with market microstructure, trading behavior, and token design than with underlying carbon asset fundamentals. By integrating on-chain trading metrics with macro-structural regulatory conditions in a high-frequency framework, this study provides new evidence on how liquidity emerges in decentralized carbon markets under heterogeneous structural constraints.