Despite growing aid fatigue in the global North, the number of bilateral aid-providing states is at an all-time high and continues to expand. In this paper, we examine the paradox of new donor countries' (NDCs) dramatic growth by asking two questions. First, what is driving donor proliferation? And second, what sort of donors are emerging from this rapid increase? Drawing on sociological theories of normative diffusion, we argue that an important driver is the desire to legitimise one's reputation as an advanced and influential state. We study the consequences of donor proliferation through a quantitative analysis of 26 NDCs, comparing their achievements to those of traditional donors on three metrics of aid quantity and quality. Our results reveal that NDCs may be adopting the traditional donor form, but not its associated functions and responsibilities, creating a gap between policy intent and practical implementation. While NDCs are contributing to global development's ongoing viability, vigilance is required to preserve its robustness.