This paper surveys the literature on costs and benefits of South–South versus North–South economic exchanges. Unlike the case for North–South exchanges, academic work on South–South economic relations has been historically limited given their marginal importance in the global economy. After the 1990s, the literature has changed in two main ways. First, South–South trade and finance since then has increased dramatically, leading to a bourgeoning literature on the topic. Second, the rise of the Emerging South has opened up new lines of inquiry to include not just the traditional topics of trade and preferential trading agreements, but also cover technology transfer, capital flows, labor migration, institutions, and environment. We discuss how this literature has evolved to take into account the greater complexity of South–South relations with a focus on China in Africa as well as the blurring of the lines between heterodox and mainstream analysis of South–South relations. We end the review by showing how the empirical and theoretical literature is exploring the increasing divergence within the global South between what we refer to as the Emerging South and the Rest of South.