Zhiguo He (University of Chicago)
The rise of centralized mining pools for risk sharing does not necessarily undermine the decentralization required for public blockchains. However, mining pools as a financial innovation significantly escalates the arms race among competing miners and thus increases the energy consumption of proof-of-work-based blockchains. Each individual miner’s cross-pool diversification and endogenous fees charged by pools generally sustain decentralization — larger pools better internalize their externality on global hash rates, charge higher fees, attract disproportionately fewer miners, and thus grow slower. Empirical evidence from Bitcoin mining supports our model predictions, and the economic insights apply to many other blockchain protocols, as well as mainstream industries with similar characteristics.