Child benefit withdrawal will make it better to work less for families with over seven children

And come 2076, that will be the case for every family in the nation.

The child tax credit withdrawal, taking effect on Monday, will lead to marginal tax rates of over 100 per cent on families with more than eight children earning between £50,000 and £60,000.

The IFS explains how the marginal rates are calculated:

Affected taxpayers will pay back one per cent of their family’s Child Benefit for every £100 by which taxable income exceeds £50,000. One per cent of Child Benefit is £10.56 per year for a 1-child family, and an additional £6.97 per child for larger families. Hence the marginal tax rate between £50,000 and £60,000 is increased by about 11 percentage points for the first child and by an additional 7 percentage points for each subsequent one. So, for example, while about 320,000 people will find that their marginal income tax rate increases to more than 50%, about 40,000 of them - those with three or more children - will find that it jumps to at least 65%.

They offer a chart with the rate calculated up to four children:

By seven children, the marginal rate rises to 99.35 per cent, and by eight, it breaks 100 per cent (106.32 per cent, to be exact). This means that any individual with a family of eight kids earning between £50,000 and £60,000 would be better off if they reduced their salary back down to £50,000. In fact, for that individual, they would have to earn £61,105 before their post-tax income was the same as it was at £50,000.

It's unclear whether any families actually exist matching that criterion - rather wonderfully, my back-of-the-envelope maths (which assumes that the exponential decrease in the number of families of each size continues: e.g., there are 1/8th the number of families with three or more kids as there are with two or more, so I'm assuming that there are correspondingly 1/8th the number of families with four or more as there are with three or more, and so on) suggests that there may be exactly one – but even if there are none at the moment, there's no reason why there won't be one in the future. Families with eight children do, after all, exist.

In fact, as time goes on, this problem will get worse. The IFS points out that child benefit is uprated with inflation, while tax bands aren't. Currently, each extra child after the first increases your "marginal tax rate" by around seven per cent, but suppose child benefit is uprated by two per cent a year. In that case, the marginal tax would exceed one hundred per cent for families with seven children next year; for six children in the year 2020; for five children in the year 2028; and, eventually, for families with just one child – i.e., every family – in the year 2076.

Hopefully the law will be changed before then, of course. But as a rule of thumb, laws which become ridiculously damaging unless you actively intervene ought not be signed in the first place. Oops.

Children. Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

Photo:Getty
Show Hide image

There's something missing from our counter-terrorism debate

The policy reckoning that occured after the 2005 terrorist attacks did not happen after the one in 2016. 

“Once the rockets are up, who cares where they come down? That's not my department, says Wernher von Braun.” That satirical lyric about Nazi rocket scientists has come to mind more than few times watching various tech giants give testimony in front of the Home Affairs Select Committee, one of the underreported sub-plots of life at Westminster.

During their ongoing inquiry into hate crime in the United Kingdom, committee chair Yvette Cooper has found a staggering amount of hate speech being circulated freely on the largest and most profitable social media platform. Seperately, an ongoing investigation by the Times has uncovered how advertising revenue from Google and YouTube makes its way straight into the coffers of extremist groups, ranging from Islamist extremists to white supremacists and anti-Semites.

One of the many remarkable aspects of the inquiry has been the von Braunesque reaction by the movers and shakers at these tech companies. Once the ad revenue is handed out, who cares what it pays for? That’s not my department is the overwhelming message of much of the testimony.

The problem gains an added urgency now that the perpetrator of the Westminster attacks has been named as Khalid Masood, a British-born 52-year-old with a string of petty convictions across two decades from 1982 to 2002. He is of the same generation and profile as Thomas Mair, the white supremacist behind the last act of domestic terrorism on British shores, though Mair’s online radicalisation occurred on far-right websites, while Masood instead mimicked the methods of Isis attacks on the continent.  Despite that, both fitted many of the classic profiles of a “lone wolf” attack, although my colleague Amelia explains well why that term is increasingly outmoded.

One thing that some civil servants have observed is that it is relatively easy to get MPs to understand anti-terror measures based around either a form of electronic communication they use themselves – like text messaging or email, for instance – or a physical place which they might have in their own constituencies. But legislation has been sluggish in getting to grips with radicalisation online and slow at cutting off funding sources.

As I’ve written before, though there  are important differences between these two ideologies, the radicalisation journey is similar and tends to have the same staging posts: petty criminality, a drift from the fringes of respectable Internet sub-cultures to extremist websites, and finally violence.  We don’t yet know how closely Masood’s journey follows that pattern – but what is clear is that the policy rethink about British counter-terror after the July bombings in 2005 has yet to have an equivalent echo online. The success of that approach is shown in that these attacks are largely thwarted in the United Kingdom. But what needs to happen is a realisation that what happens when the rockets come down is very much the department of the world’s communication companies. 

Stephen Bush is special correspondent at the New Statesman. His daily briefing, Morning Call, provides a quick and essential guide to British politics.