This paper provides a nice and clean characterization of a decentralized learning problem. The result is perhaps unsurprising in its form, but the analysis is far from trivial. There are some nontrivial assumptions for their results to hold which perhaps limit the scope of this result but do suggest interesting avenues for future research in this increasingly important area. Overall, this is a solid contribution and should be of interest to NeurIPS attendees who work in optimization and distributed systems.