Two-sample test of stochastic block models via the maximum sampling entry-wise deviation

The paper discusses a statistical problem related to testing for differences between two networks with community structures. While existing methods have been proposed, they encounter challenges and do not perform effectively when the networks become sparse. We propose a test statistic that combines a method proposed by Wu and Hu (2024) and a resampling process. Specifically, the proposed test statistic proves effective under the condition that the community-wise edge probability matrices have entries of order \(\Omega (\log n/n)\), where n denotes the network size. We derive the asymptotic null distribution of the test statistic and provide a guarantee of asymptotic power against the alternative hypothesis. To evaluate the performance of the proposed test statistic, we conduct simulations and provide real data examples. The results indicate that the proposed test statistic performs well for both dense and sparse networks.