@EEexpat
For a long time in the UK, people on low earnings are not much better off, if at all, compared to people claiming benefits. I worked in the Netherlands for several years and it was the same there. My daughter works in German and says the same. So, the gap between earnings and benefits needs to widen, but how?
We need to look at the "marginal" rates of tax compared with "marginal" loss of benefits when people move off benefits into paid work, or those already working but on benefits who are thinking of working more hours, taking promotions, etc.
It's no surprise that people don't work, or don't take extra shifts/promotions, when they'll be hardly any better off, i.e. the additional (marginal increase in) wages is taken by tax/nic combined with reduction in benefits, and at some income levels, they can be worse off.
We need to have an "over-ride" where, regardless of your income, you can't be worse off, and will always be better off, by at least 50% of your "extra" marginal earnings. I.e. someone on UC with a little part time job, getting an extra shift, of say £50 of earnings, MUST get to keep at least £25 of that, taking into account everything, i.e. loss of UC, tax, nic, student loans, housing allowance, council tax relief, etc etc. Otherwise just why would they do it? Especially if it involved a bus, train or taxi journey costing them money, or an extra couple of hours paid child care or after school club, or whatever.
Take it right up through the income levels, i.e. apply the same at £60k threshold where you start to lose child benefit, the £100k threshold where you start to lose personal allowance and lose free child care, etc etc.
Yes, it'd be complicated, but the benefits would be enormous. We keep hearing the soundbite "make work pay", but until we deal with the tax/benefit trap where people can be worse off or only marginally better off, by working more, taking promotions, etc., we'll never escape from the benefits death spiral.