I write occasionally on Glass Sibling issues, partly because, there are relatively few other people doing it.

There are 495,250 Glass Siblings under 16 in the UK. This post details how I worked that out.

Traditional research, of course, would be to send out some surveys and try and extrapolate from results. I’ve used this style before on papers, but it’s frustratingly rough. I wanted a better approach

In this case, almost all parents of children in the UK are in receipt of Child Benefit. Also almost all parents of children with disabilities in the UK are in receipt of Disability Living Allowance (DLA).

If you had a list of all the households that received Disability Living Allowance for someone under 16, and you could break that list down by the amount of overall child benefit claimed by the household, then you could count up all the siblings. You’d only count the cases where both the ‘glass‘ and the DLA sibling were under 16, but you’d get better data than ever before.

The DWP have this information, so in October 2014, I made a Freedom of Information Request asking for

“the number of people receiving Disability Living Allowance on behalf of an under-16 year
old. I would like this information broken down by the overall amount of Child Benefit claimed by the person.”

This is the sort of the thing that the Freedom of Information Act is particularly useful for. The team at the other end get that this isn’t information that people are going to shout at them over, this is information that the government can release to the public to help make the world better.

This Friday, they came back to me; Here are the figures.

**Number of Children per Household** **Frequency** **Total Number of Siblings**
1 101,100 0
2 144,590 144,590
3 81,270 162,540
4 34,310 102,930
5 12,120 48,480
6 4,200 21,000
7 1,520 9,120
8 540 3,780
9 210 1,680
10 80 720
11 30 300
12 10 110
Total **495,250**

That’s 495,250 in total. As a minimum number of the siblings (under 16) of children (also under 16) with disabilities. I haven’t worked out how to extrapolate this to the siblings under 18, or adults. But I think that’s a very, very big number considering the tiny amount of attention paid to it.

Note – lots of caveats can be put in here, but I wanted to put these numbers out. This is clearly only one datapoint, but the DWP figures are as solid as one can imagine. For those interested, you can compare with the Office for National Statistics numbers here