It's pretty long and will take me a while to get through it, so perhaps over the next few days I'll develop a different view on the following comment, as I learn more.

The workings of the benefits system may seem a long way removed from the
measurement of unemployment. The point is however that for many of the longerterm
jobless who have health problems, the differential in benefit payments creates
an incentive to claim IB rather than JSA. For example, an unemployed man with a
wife in work and perhaps a small pension from a previous employer will not generally
be entitled to means-tested JSA. In essence, his wife's earnings and his pension
reduce or eliminate his JSA entitlement. But if he has sufficient health problems, and
if he has enough NI credits (which most men with a work history do have), he will be
eligible to claim Incapacity Benefit irrespective of his wife's earnings or in most
circumstances of his pension as well.
5
The gatekeepers determining access to Incapacity Benefit are medical practitioners -
initially the claimant's own GP but for claims beyond six months doctors working on
behalf of the Benefits Agency. To qualify for IB a person must be deemed not fit
enough to work. In practice, however, the tests applied by the Benefits Agency
assess ability to undertake certain basic physical tasks rather than inability to do all
kinds of work in all circumstances. Many unemployed people have picked up injuries
over the course of their working life, and there is the effect on health and physical
abilities of simply getting older. In practice, therefore, many of the unemployed with
health problems are able to claim IB rather than JSA. As IB claimants they are not
required to sign-on fortnightly or to look for work. Instead they will typically be
recalled for medical re-assessment only once every two or three years.
The diversion onto Incapacity Benefit distorts both official measures of UK
unemployment.

Also, although Incapacity Benefit payments start at almost the same rate as JSA they increase after six months and
again after twelve months

So if I'm a 50 year old bloke with a back injury incurred at work, maybe playing golf, and i have some bad luck and get laid off my job, would not I find it kind of tempting to look at this as an option.  Back cases are notoriously difficult to diagnose, and understand.  And my back really has given me some problems over the years--just not enough to quit.  But now i see that I can get my company pension (? could you do that in the UK,,,you can in the US, and it's been a while since I lived there, but I think you could), get my Incapacity Benefits, get my wife's salary,,,,maybe do a few odd jobs under the table on the side?  Or maybe like my brother in law, get a clean up job at the local, and when you're not cleaning up just have a few pints.  Sounds like a pretty good early retirement.  And of course it would be even more tempting if jobs in the area really were a little hard to come by.  Most people when they retire find their work related expenses were more than they realized, so his spending probably goes down as well, to offset the shortfall from his job income to this type of income.

What do you think?  And as I said, I'll keep reading to see if they've dug into this,,,but we've had problems in the US with the previous welfare program and some of the state's current disability programs.