The problem of “problem families” is much larger than we could ever imagine. Louise Casey, head of the government’s Troubled Families programme, delivered this stark conclusion at the end of her three-year operation. There are not 120,000 families, as we previously thought, there are 500,000. So the cost is not £9bn – the figure calculated in 2012 – it is £30bn.

To recap: Casey was given this charge back in 2011, after the riots. The figure then for families afflicted by these “troubles” came from a study in 2004, when families were counted who met five of seven criteria: having a low-income; no one in the family working; poor housing; parents with no qualifications; the mother has a mental health problem; one parent has a long-standing illness or disability; and the family is unable to afford basics, including food and clothes.

Two studies, now two years old, reached the same broad conclusion: that this is a misuse, even an abuse, of data. The 120,000 represents people who are poor: what the government has counted is people in extreme deprivation, yet what it describes is families who are disruptive. There is no systematic statistical attempt to overlap the poverty with delinquency, yet that is what the euphemistic word “troubled” is meant to convey.

“Troubled” itself is Orwellian and means its opposite: “causing trouble”. The attempt to put a price tag on these families – each of which is said to cost the taxpayer £75,000 a year – is misaligned. The £75,000 is a mix of what the families cost in benefits and interventions.

But only poor people are weighed and measured by how much they cost the country. In fact, all of us, one way or another, represent a cost: whether by living too long or studying too much or mismanaging complex financial products. Each of us could have a price tag stuck on our heads that the rest of society could then resent us for. But for some reason this is not thought at all relevant unless you have cost the wrong kind of money. What this proves most of all is the dearly held politician’s dream: that accuracy – ultimately truth – does not matter. You can simply give a statistic and, whether or not it is disproved, people who like it will still be using it two years later.

So the news that the real problem extends to half a million families – delivered by Casey in a Sunday Times interview – should not cause the alarm that, say, a real statistic would. Yet it is interesting as a demonstration of how the territory has changed.

As ever, you get much more anecdote than evidence. A senior police officer is quoted saying: “I could park a police officer on the settees of some of your families 24 hours a day, they are that demanding of our services.” But when you dig for detail on which services in particular these families require, the persistent criminal behaviour described is domestic violence. Now this, like any other crime, has a perpetrator and a victim. As soon as you bracket this as the kind of thing that happens in a “problem family” you collapse that distinction. There are no moral differences here. You are neither good nor bad in a problem family, you are simply “problematic”.

There is still victimhood in domestic violence scenarios: the children are still taken as victims by family courts and other agencies. But the mother is an accessory to the crime of having exposed the children to the violence of which she was the target.

Poor health is a feature, though whether they are using it as a diagnostic tool – identifying a “problem” family by its obesity – is never entirely clear. “Many are affected from their mid-30s by chronic health problems including diabetes and heart conditions, which are normally associated with old age,” the Sunday Times reports. These are metabolic conditions caused by the overconsumption of sugar. They have rocketed because the food industry adds too much sugar to food, not because an underclass has suddenly forgotten how to look after itself.

The problem is worldwide. If you lack the organisational skill to get your kids to school on time, how on earth would you have the capacity to coordinate your irresponsibility with that of a fat person in Malaysia? The answer is simple: stop corporations adding unnecessary sugar to processed food. But nobody ever suggests that, because the government’s scientific advisory committee on nutrition is packed with people employed by the sugar industry.

It is terribly convenient for obesity and associated syndromes to be the fault of the people they afflict. Underlying all this is the insistence that poor people are poor because they are worse at life. They may not be able to help it, they may be so inadequate that you cannot technically blame them for their lack of self-control. Nevertheless, there it is: the root of all their troubles is their inability to discipline themselves. Obesity is a lack of discipline made flesh. Politically, it is wonderful. It makes the feckless instantly identifiable and simultaneously proves how feckless they are. I understand completely why the right loves it; what I do not understand is why there is no push back from the left.

This is just the start of a battle that will intensify approaching the election. Whose fault is poverty? Is it the consequence of human uselessness, or is it the result of a useless system? Pointing out the holes in the data is not enough; we have to be clear about the systemic causes of poverty: low wages, insecure jobs, deliberately insecure benefits, high rents, impossible energy costs. Everything else is window dressing.