About the firm

A multidisciplinary consultancy built around evidence.

AO Group and Services brings together economists, analysts and policy specialists to produce analysis that is rigorous, transparent and fit to inform decisions of consequence.

Our purpose

We exist to raise the evidential standard of important decisions.

Public bodies, regulators and infrastructure organisations make decisions of lasting consequence, frequently under scrutiny and rarely with perfect information. The quality of those decisions depends, in large part, on the quality of the evidence behind them.

AO Group and Services was established to meet that need: to provide independent, rigorous analysis that connects complex data to the choices our clients face. We work across economic consulting, health economics, policy analysis and market intelligence — disciplines united by a single commitment to evidence.

Our work draws on experience across UK government analytical work, sector intelligence, health economics and regulatory analysis. It is informed by an understanding of the institutional context in which our clients operate.

Consultancy philosophy

Three principles shape every engagement.

Evidence over assertion

We do not offer opinion dressed as analysis. Every conclusion is traceable to a method and a source, and every assumption is stated where it can be examined.

Rigour with restraint

We are precise about what the evidence can and cannot support. Where data is incomplete, we say so — and we are explicit about the uncertainty that remains.

Built to be acted on

Analysis that cannot inform a decision is of little use. Our outputs are structured around the choices our clients actually face.

Analytical approach

Methodology that is transparent by design.

Our methods are grounded in established analytical frameworks — HM Treasury Green Book appraisal, recognised health economic modelling standards, and the principles of good regulation. We use these frameworks not as a compliance exercise but as a discipline for producing defensible evidence.

Reproducibility is central to how we work. Analysis is documented so that it can be understood, audited and maintained by others — including, where appropriate, our clients’ own teams. Evidence that cannot be examined is evidence that cannot be trusted.

Areas of expertise

Economic appraisal & cost-benefit analysis
Health economic modelling
Econometrics & quantitative methods
Policy analysis & options appraisal
Market intelligence & sector monitoring
Regulatory impact assessment
Data engineering & analytics
Evidence synthesis

Disciplines & methods

Trained economists and analysts, applying quantitative method.

Our work is led by economists and quantitative analysts with experience of public sector analytical standards. We combine applied economics with the statistical and data skills needed to turn evidence into decisions — from econometric estimation to cost-effectiveness modelling.

We work in the tools the analytical profession relies on, and we hold our work to the same standards expected of government analysis: documented, reproducible, and defensible under review.

Core disciplines

Economics
Econometrics
Health economics
Statistical analysis
Quantitative modelling
Public policy analysis
Evidence synthesis
Impact assessment

Methods & tools

RPythonSTATAEconometric modellingCost-effectiveness analysisReproducible pipelines

Quantitative methods applied with transparency — every model documented, every assumption stated, every result reproducible.

Leadership

The economists behind the analysis.

David Mensah

Economist

Focus areas

Economic analysisEconometricsImpact assessmentPolicy evaluation

David Mensah is an economist specialising in economic analysis, econometrics, impact assessment, and evidence-led policy evaluation across public and private sector environments.

His experience includes economic appraisal, regulatory analysis, market intelligence, quantitative modelling, and strategic evidence development to support complex organisational and policy decisions. He has led analytical work involving business cases, sector monitoring, procurement economics, and economic evaluations aligned with HM Treasury Green Book principles.

Alongside his public sector experience, David leads consulting engagements through AO Group and Services, supporting organisations with economic modelling, analytical strategy, evidence synthesis, and data-driven insight.

His work combines applied economics with rigorous quantitative analysis and a strong focus on defensible methodologies, transparency, and clear communication for decision-makers.

Dr. Joseph Prince Mensah

Health Economist

Focus areas

Health economic modellingMicrosimulationCost-effectiveness analysisR · STATA

Dr. Joseph Prince Mensah is a health economist specialising in public health economics, decision sciences, and advanced quantitative modelling for healthcare and policy evaluation.

His expertise includes microsimulation modelling, cost-effectiveness analysis, statistical modelling, and evidence synthesis, with particular focus on evaluating long-term public health interventions and health system outcomes.

Joseph has contributed to research and consultancy projects spanning cardiovascular health, obesity, infectious disease, Long COVID, and population health policy. His work has involved collaboration with institutions including the University of Oxford, the University of Sheffield, and international policy stakeholders.

He applies advanced analytical methods using R, STATA, and health economic modelling frameworks to support rigorous, evidence-based decision-making across healthcare and public sector settings.

Work with us

Independent analysis, when the evidence has to hold.

We work with a limited number of organisations at any one time, which lets us bring senior analytical attention to every engagement. If that fits the decision you are weighing, we would welcome a conversation.

Discuss an engagement Review our work