First published in response to Christian Guy's article in the Huffington Post, June 2016.

Measurement is a tricky business, even in science and engineering. How much more so, then, in complex matters of public policy and the subjective experience of millions of people? Christian Guy has raised the obvious and widely agreed fact that child deprivation is a multi-faceted problem, demanding attention not only to income levels, costs of living and housing, but also lived experience, discrimination and stigma, education, health, intergenerational relationships, access to services, neighbourhood conditions, local economies, and much more.

Children living in poverty are quite capable of powerfully expressing what poverty really means to them. When asked to offer photographs of their lives they have shown us pictures of empty fridges, derelict buildings covered in graffiti, overcrowded bedrooms that double as their family kitchen, boring and menacing public spaces in which they are meant to play. Real people are not data, nor are their unique qualities, experiences and worth to be measured by money. On this he and I could probably agree.

Indeed the agreement that child poverty is a multi-faceted phenomenon among all those who are fighting against it is ubiquitous. Back when the current child poverty measurement system was constructed the entire voluntary sector contributed their views. A rare but wholesale consensus emerged that any measurement system based solely on income would fail to capture the true nature of child poverty, but that any measurement that did not keep clear track of what was happening to incomes would be a nonsensical way of quantifying poverty, let alone being able to know whether we had succeeded in what was then a cross-party as well as cross-sector commitment to eradicate it.

No single measure is perfect. It is a way of gauging and comparing, to give us useful indications and intelligence. Repeating any measurement the same way over time can produce important pictures of trends and changes, while all intelligent users of such data will be mindful of its limitations and what stories it leaves untold.  Economists are quite used to this profound imperfection of measurement. GDP as a singular measure of economic health, for example, is so widely discredited that no economist worth their salt will use it on its own to diagnose the health of an economy, without interpreting it in balance and contrast with others, like productivity, trade balance, unemployment. Christian Guy’s call for more and additional indicators to provide a fuller picture of child poverty is merely a reflection of what already happens among all of today's child poverty campaigners. No one who has heard the rising alarm and widespread campaigning about food banks, household debt, childcare costs and fuel poverty could doubt there are many angles and issues to be tackled.

Having used the same definition and measurement framework for fifteen years, what we can say today is that more children are living in absolute poverty, as defined by that measurement framework, than there were last time we measured. Thousands upon thousands more. That growth in inadequate family incomes has taken place over the same period of time as the government has been keen to celebrate an economic recovery defined, ironically, by one simple income measure - GDP growth. Absolute poverty’s gone up and GDP's gone up. The two measures both tell us something important, but neither tells us everything we need to know if we are to hold government to account for their policies, nor indeed if we are to redouble our efforts on child poverty. If we do have to question our measurement systems or definitions today, then surely it must be the official definition of an economic recovery. What kind of an economic recovery can it really be if more children are going without their most basic needs being met?

The claim that government has been hamstrung and constrained by the Child Poverty Act's focus on income inequality is not borne out by experience, nor are any examples offered to support it. The Act clearly had no constraining impact when the coalition government passed the law freezing all benefits to parents for three years at a time of high cost of living increases. It had no impact in preventing the creation of the benefits cap or the bedroom tax. It has had no impact in preventing the explosion in benefit sanctions on parents with children who depend on them. Many people were dubious in 2010 that the Act would be effective in levering real change, and many others may in fact wish the Act had greater teeth with which to curb such policies, but so far it simply hasn't.

Every child and every parent knows that money isn't everything that’s important in life. Every child who feels alone and unloved, or who cares for a parent suffering from addiction or mental ill health, knows that no amount of money can make up for it. There are, let us not forget, many children of affluent parents who know the pain of such experiences, and they are equally deserving of our support, intervention and commitment to counter it without us needing to redefine them as 'poor'. But to claim that a consistent focus on what is happening to families' income is to 'lose sight of what it means to understand and fight child poverty' is a bizarre charge. However much they have at their disposal, every parent in the country knows how important their income is to the quality of life they are able to create for their whole family, and that poverty, if it means anything, means not having enough money to make ends meet.

We owe it to everyone, whether they have children now or not, to ensure that each and every job in this economy pays a Living Wage or more on which to live, no matter whether their employer is the state, a private company or a charity. The real unsustainable merry-go-round is the false economy of state subsidy for low pay. That won’t ever be solved by simply taking the subsidy away from the low paid families who rely on it; it can only be solved by making employers pay properly for the workers they hire and building that true cost of employment into their budgets and business models. The truth of that stares us all in the face, whatever angle you look from, whatever statistics you might be reading or whichever report you are reacting to. That is the kind of 'revolution' needed to fight child poverty with courage, and to save millions of pounds from the working age welfare bill forever. Arguing over how we should measure it, when millions of children today are actually living it, is a distraction and not a revolution.