Audit, statistics and the published number

The supreme audit institution — an auditor-general or a court of audit — audits every public body and every public account. INTOSAI's Mexico Declaration (2007) sets eight conditions for its independence:

1. A legal framework in the constitution or in law.
2. The head appointed for a fixed term, secure in office, immune from suit for audit work done in good faith.
3. A broad mandate and full discretion over what to audit.
4. Unrestricted access to information.
5. The right and the duty to report, at least once a year.
6. Freedom to decide the content and timing of reports, and to publish them.
7. Follow-up of its recommendations.
8. Financial and administrative autonomy: its budget is not set by those it audits.

It reports to the assembly, not to the executive.

Financial audit: every year the auditor gives an opinion on whether each public body's accounts are complete and true, and whether money was spent as the assembly voted. Keep the accounts to a published standard — accrual double entry, as in the ledger, and the International Public Sector Accounting Standards (IPSAS) — and audit them within months of the year's end, not years.

Performance audit: a programme of reviews asking whether a service achieved what it was funded for, at what cost per unit, and how that compares with alternatives. Choose topics by size and risk, by a published method, not by request.

A finding nobody answers is wasted work. Enter every audit finding in a public register with the finding; the recommendation; the body's written response within a fixed period; the action promised and its date; and the auditor's check that it was done.

The assembly's accounts committee holds a public hearing on each major report and calls the head of the body to answer in person. In the UK the Public Accounts Committee is, by convention, chaired by a member from outside the governing side, so the government is not examining itself. Report every year the share of findings closed, open and overdue.

Bring the census and all official figures into one statistics office, whose head serves a fixed term with the sole say over methods, content and release timing. Write the UN Fundamental Principles of Official Statistics into its law. Their core:

• Impartiality, and equal access for every user.
• Methods chosen on professional grounds alone, and published.
• The right to correct misuse of its figures in public.
• Individual data strictly confidential, used only for statistics.
• International standards, so figures compare across places and years.

Announce release dates up to a year ahead, and keep them. Release at a fixed hour, to everyone at the same moment — no early copy for ministers or anyone else. The UK ended routine pre-release access for ministers to its national statistics on 1 July 2017, when the National Statistician judged that it damaged public trust in the figures.

With each release publish the method, the margin of error, and every revision to earlier figures. Announce a late or cancelled release with its reason.

With computing and the network, publish the budget, every payment above a set value, every contract and every audit report as open, machine-readable data, free and licensed for reuse. Anyone can then check a total, trace a payee, or compare prices.

Use open standards — the Open Contracting Data Standard for public purchasing — and keep the raw data, the code that produced each statistic, and its description in the redundant archive. Statistical disclosure control — suppressing or rounding small counts — keeps individuals unidentifiable in published tables.

When a measure becomes a target, it ceases to be a good measure — Goodhart's law, 1975. A hospital judged only on waiting times reclassifies its waiting list; a school judged only on pass rates enters only its likely passes.

Guard against it: use several indicators for each service, including one the service cannot easily move; have the statistics office collect them, not the service itself; audit the data behind any target that carries money or careers; and report outcomes — lives saved, children able to read — beside outputs.

An independent fiscal office, set up under the OECD Principles for Independent Fiscal Institutions (2014), publishes the cost of each major proposal over at least 10 years, and a yearly projection of the public finances, before the assembly votes. It does not judge whether a proposal is good; only what it costs and who pays.

With audit and statistics it closes the loop — what will it cost, what did it cost, what did it achieve — each answered by an office that the people asking for the money do not control.