A “one-woman collection of supermarket receipts”, as she described herself to me earlier this year, food writer and cookbook author Jack Monroe has become an “accidental inflation analyst”. In doing so she’s also become a hero. And more specifically The Grocer’s Hero of the Year. 

The campaigner, whose “grouchy tweets, written in bed” one morning, challenged entrenched economic orthodoxy and changed the way officials track food inflation. 

Her comments, posted at 12:30pm on a Wednesday afternoon last January, even drove a major change of direction at one of the UK’s biggest supermarket chains. Jack Monroe’s impact this year is undeniable. And it all started with a tweet.

Monroe argued back in January that the system by which we measure the impact of inflation is fundamentally flawed. That it “completely ignores the reality and the real price rises for people on minimum wages, zero-hour contracts, food bank clients, and millions more”.

The thread included numerous examples where some of the biggest price hikes were hitting the cheapest products. At a local Asda, for example, some of the cheapest available rice had gone from 45p/1kg to £1/500g. The same went for items such as curry sauce, apples and pasta.

It was not simply due to the price rises themselves, Monroe argued, but because supermarkets were slashing value ranges upon which poorer families rely, as there was insufficient margin in them.

For Monroe, there was nothing particularly special about what she was writing. As an anti-poverty campaigner, it was, after all, a point she’d been making for 10 years. But this time, it struck a nerve.

Monroe was suddenly in every newspaper, on every TV channel and radio station, arguing that the traditional measure of inflation was flawed.

It is at Asda though where the impact has perhaps been felt the most. The examples Monroe had given, using those supermarket receipts she collected, had all come from shopping at her local Asda. In February, just weeks after Monroe launched her tirade, Asda committed to stock its entire Smartprice budget range in all 581 supermarkets as well as online, so it was now available to hundreds of thousands of shoppers for whom it was previously unavailable.

Monroe was quick to heap praise on Asda for its ranging u-turn. In fact she was reduced to tears.

An essential voice for thousands

But Asda didn’t stop there. In March, it relaunched its value range as Just Essentials, and in doing so more than doubled the number of items in the range. Today, there are more than 260 products in its value range, placing it behind only Tesco.

On launching in May, some thought the bright yellow packaging of the Just Essentials range acted as a “poverty marker” – but most shoppers disagree, with two-thirds of shoppers picking up at least one item from the range, Asda reported in October.  

In fact, the biggest criticism you could reasonably level at Asda is that it didn’t order enough stock. For months it kept selling out of Just Essentials products, forcing Asda to ration customers to three products each. It’s only in the last month the rationing has been lifted. In the meantime the ranging overhaul has contributed to a dramatic turnaround in Asda’s fortunes.

Of course, it’s impossible to make a direct link between Jack Monroe’s comments and Asda’s wholehearted change of direction, but Asda appears to have rediscovered its purpose as a champion of value in the cost of living crisis, and the range re-engineering appears integral to a greater focus and drive.

The renewed sense of purpose has also manifested itself in Asda’s pioneering launch of its Kids Eat for £1 initiative, which launched initially in time for the summer holidays (since extended to the end of the year), and the more recent £1 soup and a roll ‘winter warmers’ offer for OAPs in November. Asda has served over one million meals in its cafés in the ensuing months.  

Monroe’s impact has also been felt among the number-crunchers at the Office for National Statistics, who evolved their inflation tracker to include a wider range of income levels. ONS were of course already aware of the issue that average ‘headline’ figures mask the extreme effects at both ends, but Monroe’s work directly prompted them to trial changes to their collection methods.

ONS continues to emphasise its work is “highly experimental”, but the latest release in October found the cheapest groceries were rising at 17% compared to the average of 15%.

Is it enough of a gap to prove Monroe’s argument? That’s a debate in itself. And work to develop a Vimes Boots Index – a reference to the principle, as stated in a Terry Pratchett novel, that the wealthy stay wealthy as their wealth enables them to spend less money – is still ongoing. But there is no arguing that Monroe has reminded supermarkets they have a responsibility to help their poorest customers. It’s a lesson we hope they’ll never forget. 

Monroe has even inspired The Grocer directly. In April, we altered the methodology used to measure price inflation in our Grocer 33. Instead of calculating the price increase based on the average over the previous 28 days (versus the previous 28 days or 28 days year on year), a spot price is taken, so the immediate effects of price inflation can be calculated. 

And last month, The Grocer launched a new Key Value Items tracker. A weekly index, it measures the price of hundreds of essentials, including a number of value or entry-price-point products, across Aldi, Asda, Lidl, Morrisons, Sainsbury’s, Tesco and Waitrose. 

Big data can tell us a lot about inflation and the cost of living crisis. But a one-woman collection of supermarket receipts has exposed the flaws in all those millions of data points and shamed supermarkets into changing direction. And that makes Monroe The Grocer’s Hero of the Year.