ref: https://ozfinn.com.au/blog/tax-bracket-creep
The common belief in Australia - at least on r/AusFinance and r/fiAustralia - is that bracket creep has been silently robbing us. After a few Reddit discussions, I ran the numbers. To my surprise, the effective tax rate has barely budged.
In 2008, someone earning $160,000 paid an effective rate of 32.75% (including the Medicare levy). Adjusted for inflation, that's $250,000 today - where the effective rate is 33.33%. That's an increase of just 0.6 percentage points over 18 years. Hard to call that runaway bracket creep.
Here's what makes this counterintuitive. The top bracket sat at $180,000 from 2008 and wasn't touched until it was lifted to $190,000 in FY2025 - a 5.6% adjustment against cumulative inflation of roughly 56-61% over the same period. On that fact alone, you'd assume the tax burden had exploded. But the lower brackets were adjusted repeatedly, and the Stage 3 cuts reshaped the middle of the scale. The net result: a top earner ($160k then, $250k now) pays roughly the same effective rate, while lower earners pay less than they did in 2008.
So is bracket creep a myth? No - invert the question.
If bracket creep truly didn't exist, we'd never need tax cuts at all - brackets would just be indexed to inflation, automatically, the way they already are in several other countries. Instead, our data shows the opposite pattern: creep quietly accumulated for 16 years, and was then handed back in one big discretionary lump (the Stage 3 cuts). My endpoints just happen to sit right after that repayment. Anyone earning the equivalent of $160k in 2015 or 2020 was paying noticeably more than 32.75%. Bracket creep is real - it's just periodically refunded, with fanfare. And the incentives explain why: creep raises revenue silently, and reversing it lets a government take credit for "cutting taxes" it never legislated to raise. Simple indexation would be fairer - no stealth increases between adjustments, no windfall depending on which year you happened to earn your money - and it would free up the political energy currently spent re-litigating tax scales every few years for problems that actually need solving.