Measuring What Matters

Measuring What Matters. Getting the best value from infrastructure investment is a research report released in partnership with WSP.

Infrastructure investment decisions shape the long-term trajectory of Aotearoa New Zealand's economy, society, and environment. Whether a road, a flood defence, or a hospital, these are decades-long commitments that impact the country’s future trajectory financially, socially, and environmentally.

This makes the question of how we measure value in infrastructure investment fundamentally important. How we measure value as a country shapes what actually gets built – and getting this as right as possible is of fundamental importance to Aotearoa New Zealand's future.

Aotearoa New Zealand spends billions of dollars on public infrastructure every year, yet there is no mandated process to ensure we receive value for money from those investments, and very limited attempt to evaluate the extent to which projects achieve the outcomes that they set out to achieve. Instead, at times the use of urgency combined with shifting priorities has limited the role of evidence and process in investment funding decisions.

Meanwhile, in a context of increasing fiscal constraints, there has of yet been no systematic attempt to prioritise between different types of infrastructure investment to ensure the country invests its limited funds in the most cost-effective way. Misalignment between identified investment needs and available funding is regularly absorbed through deferral, cancellation, and accumulating deferred maintenance rather than managed strategically.

Social cost benefit analysis (CBA) is the primary tool available to ensure public investment is as efficient and evidence-based as it can be. CBA provides a disciplined, systematic, and transparent way to assess investment options – quantifying and, where possible, monetising the full range of costs and benefits, including social and environmental impacts, and making the assumptions underpinning decisions open to scrutiny and democratic challenge.

Aotearoa New Zealand has excellent tools and a well-developed decision-making methodology for CBA. The potential for its use is significant. In practice however, because its use is not mandatory, CBA is applied inconsistently across the public sector. Of six major infrastructure-intensive agencies contacted in writing for this report, only two – NZTA and Kāinga Ora – responded that they use CBA regularly and systematically. The other four responded that they either do not use it, or use it irregularly.

Over the last five Budgets, fewer than a quarter of infrastructure initiatives assessed by Treasury's Investment Panel included a cost-benefit analysis of the preferred option (Infrastructure Commission, 2026). In a similar vein, local government’s use of CBA to inform infrastructure investment decisions is the exception rather than the rule.

This report argues that addressing these weaknesses is both urgent and achievable.

Key report recommendations include:

• Mandatory use of CBA for all major central government infrastructure investments, supported by enhanced training, clear guidance, and sector‑specific tools.
• An independent infrastructure assurance framework, with the Infrastructure Commission playing a strengthened independent assurance role, and requiring publication of business cases and cost-benefit analysis.
• Routine post‑implementation evaluation of major projects to assess whether expected benefits were achieved.
• More strategic, cross‑portfolio use of CBA, supporting more consistent comparison of similar investments across sectors such as health, housing, justice, and transport.
• Closer alignment between the Budget process and long‑term investment planning, including exploring multi‑year capital budgeting.