I cracked up when I got to the marathon example. When I ran a half marathon I realized about 80% of the way through that I was on track to finish under 2:30:00 and pushed myself to make it happen. I should have guessed that sort of behavior would show up in the statistics!

The UK tax system also has a bunch of unfortunate cliffs, and tapers that create >60% marginal tax rates and worse. There's a calculator here that illustrates it well https://tax-cliffs.britishprogress.org/calculator

The childcare cliff edge is probably the worst, but the personal allowance taper isn't ideal either as it's compressed over a relatively short income range

And of course all the thresholds remain frozen, creating plenty of fiscal drag on top.

I also appreciate discontinuities and while I won't comment on the data in the paper itself without cross-referencing, I will say that a couple of these examples hold true for me from applied observation over the years. When I was old enough to start caring about insurance for health and property, or became a parent and had to begin forecasting costs for college and what loans really represented, I began looking at observable data much differently. Working in the software industry, you begin to see the complicated systems at work at the C-Level, and the seemingly odd relationships with unrelated organizations start to become clear. Being an educated voter, a discerning consumer of products, and turning a critical eye on world news all require the ability to see processes, their patterns and the discontinuities within them. While there may not always be a useful explanation behind all of them, seeing them in the first place is essential to navigating so-called reality successfully.

Would test score problem be solved if teachers graded individual questions, not entire test?

The opening story is fabricated and/or bullshit.

Last year (2025) there was no limit on income for health insurance subsidies. That ended for this year, but last year there would have been no reason for anyone who knew what they were doing to try to lose money to drop their income (especially in the cited range of $48-55k/year).

That is the case this year, in most states (thankfully not where I live), but that's not what TFA is talking about.

Suspicious? It certainly makes me skeptical that the author has got the details of the other examples correct.

I never understood why taxes or similiar absolute points aren't gradients instead.