In 2020, 3.8 million New Zealanders earned taxable income. Last year, that number hit 4.1 million. That's 290,000 more people contributing to the tax system in just four years. (Source: Stats NZ, taxable-income-sources)

Here's how we got here. Wind back to 2020: borders slam shut, migration stops, the workforce flatlines. Then 2021: still locked down, still hovering at 3.8 million. The borders don't reopen until early 2022, and when they do, the numbers start climbing. By 2023, we're at 4 million. By 2024, 4.1 million.

That's a 7.5% jump in four years. To put that in context, between 2016 and 2020, the taxable income earner count grew by just 5.3%. We've added workers faster since COVID than we did in the years leading up to it.

Some of this is natural growth: more school leavers, fewer retirees, more people entering the workforce. But a chunk of it is migration. When the borders reopened, New Zealand didn't just let people back in. We actively recruited workers to fill gaps in construction, healthcare, hospitality. The numbers show it worked.

Now consider what that means for everything else. Every hospital, every school, every road, every power line was sized for a smaller population. You've got 290,000 more people earning wages, paying tax, using services. That's roughly the population of Christchurch added to the workforce in four years.

This isn't about immigration policy being good or bad. It's about scale. When you grow your workforce by 7.5% in four years, every system stretches. GP waitlists lengthen because there are more people booking appointments. Roads congest because there are more cars. Rents climb because there are more people competing for the same housing stock.

The government collects more tax from 4.1 million earners than it did from 3.8 million. But the infrastructure those people rely on was never upgraded to match. That's the gap. That's the tension Kiwis are feeling but can't quite name.

Twenty-four years ago, in 2000, New Zealand had 2.8 million taxable income earners. We've added 1.3 million since then. But the speed matters. The last four years weren't gradual. They were a surge. And surges leave marks.