It's probably the most stupid tax system in the developed world.
In Germany you can end up in a similar situation, though I think the gap is smaller.
- bad for social mobility - incentive to work off the books
22 hours of free childcare a week is worth ~£9k a year post-tax. If either you or your partner earn a penny over £100k then you're no longer eligible for any of your children. So with two kids in nursery a penny pay rise might lead to a £30k pre-tax pay cut.
Another way to look at this is that it's providing more to the poorer families who need it more by cutting away costs for richer families.
That a single £100k salary is enough to maintain a household of two kids is neither here nor there (and also depends very much on where you live).
Means-tested only makes sense if you have a progression instead of a hard cut-off, otherwise it creates these pits of despair.
It's similar with welfare in Germany: if you have an extremely low-paying job, welfare will "top up" your income up to the same level as someone with no job. So until you break even, working an extra hour or taking a job that pays slightly more is economically pointless because it has no effect on your bottom line: every extra Euro you earn gets deducted from the welfare benefits. This encourages undeclared work, losing the government money via taxes.
> 22 hours of free childcare a week is worth ~£9k a year post-tax. If either you or your partner earn a penny over £100k then you're no longer eligible for any of your children. So with two kids in nursery a penny pay rise might lead to a £30k pre-tax pay cut.
Means testing is usually fairly expensive to administer too. It's more political point scoring than anything else.
Also I think that my calculations make the break-even point between the two different regimes a little over 100k.