So your solution is "spend a lot of extra money on social security", which is fine, but it doesn't satisfy the constraints.
But even so, smoothing out the curve some might be better overall even if the max amount drops.
Also you could extend the curve so that 'benefits' go negative at the high end. Now your budget is fine...
> Also you could extend the curve so that 'benefits' go negative at the high end
You've just invented tax, congratulations.
You have a very different definition of 'massively' than I do.
> You've just invented tax, congratulations.
Positive taxes can balance out negative taxes, ~tada~.
The original constraint was not a $0 increase. I did not violate the original constraint.
And even if you did take it to be $0, it said you can't "just afford to" increase. Proposing a tax to make up the difference meets that critera.
But even inside a hard "no more spending" constraint, it's not nearly as unsolvable as you make it out to be. It's quite possible that giving less money to people mildly below the old cliff edge, while giving more money to people mildly above it, is a net positive. That doesn't screw over people at the bottom, and it doesn't increase total cost.
Going from a hard cliff to a 90% marginal rate was obviously better, right? And going from 90% marginal rate to 85% was obviously better, right? They decided to stop at 63%. It doesn't mean that going further is a priori wrong.
And on top of all of that, smoothing out the curve to 50% very likely motivates more people in the range to work, reducing the amount of benefits they use.
If it's less than 63%, you "unilaterally extend benefits to a whole bunch of people who don't currently get them".
Let's say benefits for the unemployed are £1,000 a month (chosen to be an easy number to work with). You lose 63p of benefits per extra pound you earn. The government gives you (some) benefits up to the first £1,587 you earn. If you go to 50%, the government gives people earning up to £2,000 a month benefits, and so on, which probably includes a bunch of people who don't currently get any.
You can't change 63% without either paying much more in the way of benefits overall, or without reducing the benefits of those who can't do any work.
> It would technically bring more people into the system, but they'd be at the top end, and therefore only be receiving a small fraction of the current levels of benefits
That's not how the maths works. Assuming an even distribution of people at each wage level, changing this to 30% effectively doubles overall spend.