http://moneyweek.com/merryns-blog/the-truth-about-tax-credits/
We go on about tax credits a fair bit on here but here are a some nice tables of children vs effective gross income. e.g.
For one parent working 24 hours a week, minimum wage with three kids, equivalent gross = £40,500.
For two parents, working 35 hours a week, minimum wage with three kids, equivalent gross = £39,500
There are other examples where working 70 hours a week (2-people) gets you a lower effective gross income than one person working 24 hours a week.
I think these table even underestimate the benefits of less work e.g. The credit-claimers get free dental, the 70 hour workers pay higher commute costs and student loan repayments.(if gross pay above threshold).
I used to get angry about this, now I am just sad. I used to be motivated to do extra work, now I just turn down opportunities,. No wonder productivity is low, it's just not worth doing anything if you don't get to keep the results of your labour.
I'm lucky with a very short commute, easy job, salary sacrifice as much as possible with the aim of working part-time asap. Time for me to join the 24-hour club.
Maybe those figures above show we already have a citizens income. It doesn't matter what you do, the state allocates you £40K effective income with 2 kids.