Oceanic Games: Centralization Risks and Incentives in Blockchain Mining. (arXiv:1904.02368v4 [cs.GT] UPDATED)

To participate in the distributed consensus of permissionless blockchains,
prospective nodes — or miners — provide proof of designated, costly
resources. However, in contrast to the intended decentralization, current data
on blockchain mining unveils increased concentration of these resources in a
few major entities, typically mining pools. To study strategic considerations
in this setting, we employ the concept of Oceanic Games, Milnor and Shapley
(1978). Oceanic Games have been used to analyze decision making in corporate
settings with small numbers of dominant players (shareholders) and large
numbers of individually insignificant players, the ocean. Unlike standard
equilibrium models, they focus on measuring the value (or power) per entity and
per unit of resource} in a given distribution of resources. These values are
viewed as strategic components in coalition formations, mergers and resource
acquisitions. Considering such issues relevant to blockchain governance and
long-term sustainability, we adapt oceanic games to blockchain mining and
illustrate the defined concepts via examples. The application of existing
results reveals incentives for individual miners to merge in order to increase
the value of their resources. This offers an alternative perspective to the
observed centralization and concentration of mining power. Beyond numerical
simulations, we use the model to identify issues relevant to the design of
future cryptocurrencies and formulate prospective research questions.