Everyone knows New Zealand's population is aging. But here's what the demographic handwringing misses: the speed at which it's happening right now.

In 2020, there were 2.27 million taxable income sources for people aged 60-64. Four years later, that figure hit 2.56 million. That's an increase of nearly 300,000 in the final stretch before most Kiwis hit retirement age. (Source: Stats NZ, taxable-income-sources)

This isn't some distant problem for 2040. These people are already here. They're working right now. And in the next five years, they'll start moving from the workforce into superannuation at a rate we've never dealt with before.

The trajectory tells the story. In 2000, this age bracket generated 1.86 million income sources. By 2010, it was 1.91 million. The growth was gradual, manageable. Then something shifted. Between 2020 and 2024 alone, the increase was 296,394. That's more growth in four years than we saw in the entire previous decade.

Think about what that means for the tax base. Every person who moves from earning income to drawing superannuation flips from contributor to recipient. When that happens to 300,000 people in quick succession, the maths changes fast.

The workforce doesn't just lose their labour. It loses their income tax, their ACC levies, their KiwiSaver contributions. At the same time, the superannuation bill grows by roughly $30,000 per person per year. Multiply that across hundreds of thousands of people, and you're looking at billions in fiscal pressure appearing in less than a decade.

This is the bulge moving through the python. The baby boomers, born between 1946 and 1964, are now aged 60 to 78. The leading edge hit retirement years ago. But the trailing edge is enormous, and it's arriving now. The 60-64 cohort is swelling because there were simply more babies born in the early 1960s than in the decades before or after.

The government knows this, of course. Every budget includes projections. Every policy document mentions demographic change. But projections don't capture the velocity. When you see 13% growth in four years, you're not watching a trend. You're watching a transformation that's already underway.

And it's not slowing down. The numbers for 2023 to 2024 alone show another 65,000 income sources added to this age bracket. That's the population of Tauranga joining the near-retirement group in a single year.

The question isn't whether New Zealand can afford an aging population. It's whether we're ready for this particular wave, moving this fast, right now.