Publication
This report was originally published on odi.org on 17 September 2026 here, and is reproduced with kind permission.
Domestic revenue mobilisation is central to governments' fiscal resilience, but ambitious tax-to-GDP targets can create unrealistic expectations. So, how realistic are these targets?
One way to explore this question is to look at historical performance across countries. This paper takes stock of changes to non-resource tax revenue across 139 countries from 1990 to 2022, alongside case studies of Nepal, Uganda and Greece. It finds that large revenue gains (of more than 5 percentage points of GDP) are historically rare, but when they happen, under conditions like post-conflict recovery, crisis-driven reform, major policy change or improved tax administration, they tend to persist.
It also shows that there can be very different paths to the same revenue performance. The Tax-to-GDP ratio is an important headline indicator, but should be read alongside economic structure, institutional capacity, tax composition and distributional impact to understand the full picture.
The takeaway: historical experience suggests a gap between theoretical revenue potential and what is achieved in practice. To avoid setting unrealistic expectations, country-specific conditions, implementation capacity and historical experience should be key considerations when setting domestic revenue targets.
Published on: 17th September 2026
