How Administrative Tax Data Is Closing the Gap Between Fiscal Policy and Economic Reality
As bilateral aid to Africa contracted by nearly a quarter in 2025, the steepest single-year decline in the history of official development assistance, three African governments quietly demonstrated a more durable path to fiscal sovereignty: mining their own tax systems for the evidence needed to govern better.
South Africa, Uganda and Zambia have each established secure research data labs that give policymakers structured access to anonymised tax filings, returns and transaction records already held by their revenue authorities. The findings emerging from these labs are not academic exercises. They are reshaping budget decisions, restructuring corporate tax regimes, redirecting audit resources and informing social protection policy.
For West African governments managing sovereign debt interest payments that now consume an average of 27% of government revenues across the continent, up from 19% in 2019, the institutional model these three countries have built deserves serious scrutiny.
The Institutional Architecture: Secure Labs, Sovereign Data
Each of the three labs was developed with technical support from the United Nations University World Institute for Development Economics Research (UNU-WIDER), which facilitated knowledge-sharing across countries and helped make raw administrative data research-ready. Critically, data ownership, research agenda-setting and findings remain with the national institutions themselves.
This ownership structure matters. It distinguishes the model from externally commissioned fiscal assessments, which have long been a feature of IMF Article IV consultations and World Bank public expenditure reviews. In those frameworks, the analytical capacity and the conclusions tend to sit outside the government. These labs invert that dynamic.
South Africa’s National Treasury Secure Data Facility, the most mature of the three and the cornerstone of the Southern Africa Towards Inclusive Economic Development programme, has been operational for over a decade. Uganda’s lab sits within the Uganda Revenue Authority. Zambia’s equivalent feeds directly into budget deliberations and the work of its Tax Policy Review Committee.
What the Data Is Actually Revealing
The findings from all three labs share a common pattern: fiscal systems operating against their own stated objectives, with distortions that were structurally invisible until transaction-level data made them legible.
In South Africa, research revealed that the corporate tax system was quietly incentivising debt over equity financing, increasing corporate fragility ahead of economic downturns. That finding fed into corporate tax restructuring in the 2020 budget. A separate analysis of the Employment Tax Incentive, a wage subsidy targeting young workers in a labour market where nearly 60% of youth cannot find employment, produced a more complicated picture of impact than its designers anticipated. The evidence informed a decision to expand the subsidy during the COVID-19 pandemic.
In Uganda, researchers working through the Uganda Revenue Authority’s lab found that fewer than 15% of firms were paying both national corporate income tax and the local trade licence fee simultaneously. The compliance gap had existed for years. It had simply never been quantifiable. Separately, analysis showed that corporate tax incentives were costing approximately US$42 million in forgone revenue annually, with more than half of benefiting firms likely remaining profitable at the full statutory rate of 30%.
Zambia’s lab estimated the country’s tax compliance gap at between 47% and 56%, providing the first quantified basis for targeting audit resources. Those findings fed directly into the 2026 budget and reshaped the government’s audit strategy. A parallel investigation into VAT administration uncovered large firms generating simultaneous liabilities and credits on the same accounts, a circular administrative flow consuming institutional capacity without producing revenue. The problem was invisible without transaction-level data. Once identified, it was corrected.
Fiscal Sovereignty in Practice: From Data to Development Outcomes
Zambia’s domestic revenue contribution to the national budget rose from 55.7% in 2020 to a planned 73.1% in 2026. That trajectory reflects fiscal decisions made with increasing precision. It has also made possible a free education initiative that brought approximately 2.3 million children who were previously out of school back into classrooms.
In South Africa, microsimulation modelling demonstrated that the Social Relief of Distress grant was significantly reducing poverty precisely when a decision about its continuation needed to be made. The evidence changed what that decision could credibly be.
The chain of causation here, from research finding to fiscal decision to development outcome, is what distinguishes this model from conventional research production. These labs exist not to generate publications but to create the institutional conditions under which governments can govern with greater accuracy.
The West African Governance Gap
No equivalent infrastructure exists at scale across ECOWAS member states. The governance implications are significant. West African governments negotiating AfCFTA market access, managing ECOWAS trade flows and attempting to meet the WAEMU convergence criteria on fiscal deficits are doing so without the granular, domestically owned fiscal intelligence that South Africa, Uganda and Zambia are now deploying.
Ghana’s Ghana Revenue Authority (GRA) holds administrative data of comparable depth. So does Nigeria’s Federal Inland Revenue Service (FIRS), Senegal’s Direction Générale des Impôts et des Domaines, and Côte d’Ivoire’s tax administration. The raw material exists. The analytical infrastructure to use it systematically does not.
This gap has direct regional integration consequences. AfCFTA implementation requires governments to model the revenue implications of tariff liberalisation with precision. ECOWAS monetary cooperation discussions depend on credible fiscal data. Investor confidence in West African sovereign instruments is shaped by the perceived quality of fiscal management. All three functions are undermined when governments lack the tools to interrogate their own tax systems rigorously.
Comparative data reinforces the urgency. Ghana’s tax-to-GDP ratio has hovered around 13-14% in recent years, below the ECOWAS average and well below the 20% threshold that development economists associate with effective state capacity. Nigeria’s ratio sits even lower, around 10%. Côte d’Ivoire, at roughly 15-16%, performs better regionally but still operates without the kind of evidence infrastructure that Zambia is now using to push its domestic revenue share toward 73%.
The Policy Pathway: What West African Institutions Should Do
The UNU-WIDER model is replicable. It requires institutional will, a revenue authority with data management capacity, a legal framework governing researcher access under confidentiality protocols, and a structured relationship between the research function and the budget process.
Several West African institutions are positioned to move. The ECOWAS Commission could facilitate a regional framework for data lab development, building on existing cooperation mechanisms between member state revenue authorities. The West African Tax Administration Forum (WATAF), which already provides technical assistance and knowledge exchange across the region, is a natural convening body.
For individual governments, the first step is not technological. It is institutional: establishing the legal and procedural framework that allows anonymised administrative data to be used for policy research without compromising taxpayer confidentiality. Ghana and Senegal, both of which have demonstrated meaningful reform capacity within their revenue authorities in recent years, are credible candidates for early adoption.
The financing argument for building this capacity is straightforward. At a moment when external aid is contracting, debt service is rising and AfCFTA demands sophisticated domestic policy responses, the governments that can see their own economies clearly enough to act on what they find will be better positioned than those that cannot. The data already exists. The institutional model has been validated across three different country contexts. What West Africa’s fiscal institutions now need is the structural commitment to use it.
