RNZ ran a piece this week asking whether we should have a maximum wage as well as a minimum one, noting the Government would have to decide what the right amount for people to earn actually is. Fair question. Here's the awkward part: to answer it you'd want to know what households actually spend, on what, and how that splits by income. New Zealand measures that once every three years.

Look at the timeline in Stats NZ's household expenditure series and it reads like a metronome. 2007. 2010. 2013. 2016. 2019. Every three years, the Household Economic Survey goes out, and the share of households reporting total expenditure comes back at 100.0 every single time (Source: Stats NZ, household-expenditure-by-income). Complete coverage, clean series, no gaps in who answers.

Then the metronome skips. The next reading after 2019 is 2023. Four years, not three.

You know exactly what happened in between. COVID shut the country. Stats NZ's field interviewers couldn't knock on doors. Then came the price surge, the mortgage repricing, the rent increases. And the one instrument designed to show how a household's money gets carved up across rent, food, power and transport sat idle through the whole thing.

That matters more than it sounds. The Consumers Price Index tells you prices moved. It doesn't tell you what a family gave up to absorb it. Expenditure data does. It's the difference between knowing bread costs more and knowing that a household in the bottom income group now spends a bigger slice of everything it earns on food and housing before it buys anything else. That share, the shape of the budget rather than the size of the bill, only shows up in this survey.

So think about who's flying without instruments. A Wellington renter whose rent moved twice since 2023. A first-home buyer who signed at one interest rate and refixed at another. A family that quietly swapped the weekly shop for whatever was on special. Every one of them changed their spending pattern after the most recent snapshot was taken. The official record of how New Zealand households allocate money is from 2023, and 2023 is the newest year available in this series.

Now the honest counter-argument, because it's a good one. That 100.0 figure isn't a finding about household behaviour at all. It's a denominator: every surveyed household reports some total expenditure, so the percentage reporting is always going to be 100 by definition. It tells you the survey is complete, not that anything happened. The story here isn't the number, it's the years attached to it. And the four-year gap has a completely defensible explanation, which is that you cannot run door-to-door interviews during lockdowns. Stats NZ didn't drop the ball. A pandemic took it.

My view: a three-year cadence was defensible when prices moved slowly. It isn't now. We measure prices monthly and household budgets triennially, which means our most detailed picture of household hardship is always at least a year stale and sometimes much worse. If the debate is about what people should earn, the data on what people spend deserves to be fresher than the last election but one.