Correlation Analysis of Reward Rate in a DPoS Blockchain

In the blockchain architecture, there are various consensus methods, such as Proof of Work (PoW), Proof of Stake (PoS) and Delegated Proof of Stake (DPoS) for validator selection. A DPoS protocol works similarly to an election, where token holders vote for validator candidates. Elected validators generate blocks and receive block generation rewards. BNB Chain adopting DPoS has implemented a leveling mechanism to prevent the concentration of votes on a small number of validators. However, voting token holders do not always act in economically rational ways. This causes disparity in rewards to votes by token holders. We investigated the BNB Chain and factors related to the reward rates. We calculated Spearman's rank correlation coefficient between reward rates and several factors: the number of delegate-related transactions, the amount of delegated tokens, the rate of change in the amount of delegated tokens, and the average number of voting validators. As a result, we found that the number of delegate-related transactions has the strongest correlation with reward rates, and that there is a non-linear correlation between the reward rate and the average number of voting validators.