ONE OF our greatest local writers is the sadly missed Terry Pratchett. Because of the comic and fantasy settings of his novels, the depth his work is sometimes overlooked. But his fiction has always fizzed with ideas, and fizzed to the surface again last week in the most unexpected of places.

When Boris clears away the empty bottles and beer cans in Number Ten, he’ll find rising inflation at the top of the government in-tray. For all the bluster about how Labour can’t be trusted with the economy, the current rate of 5.4 per cent is the highest since, well, since the Conservatives were in power back in the early 1990s.

But as belt-tightening as that figure is, it doesn’t reflect how prices have risen in different parts of the economy. Jack Monroe, campaigner and food blogger, has long kept a list of prices for her online recipes. What she discovered was that at the cheaper end of the market, many prices have risen far higher that 5.4 per cent. The cheapest 500g bag of Asda pasta has risen from 29p to 70p: a 141 per cent rise. A ‘value’ bag of rice in her local supermarket had increased from 45p for a kilo last year to £1 for 500g – a 344 per cent increase.

Enter Terry Pratchett. One of his much loved Discworld characters is the policeman Samuel ‘Sam’ Vimes – who rose from being born in poverty to marrying the richest woman in the city. Vimes is a character acutely aware of money, and in the novel Men at Arms, lays out his ‘Boots’ theory of socio-economic unfairness. A good pair of boots, Vimes noted, cost fifty dollars and lasted ten years. An affordable pair of boots cost ten dollars, but only lasted two years (Vimes liked the cheaper boots as he could feel the cobbles through the thin soles and knew where he was on a foggy night).

Over ten years, Vimes realised, a rich person would spend fifty dollars on boots, ‘while a poor man ... would have spent a hundred dollars on boots in the same time and would still have wet feet.’

Jack Monroe has taken up Pratchett’s idea, and with the permission of his estate is creating the Vimes Boots Index to track the rising cost of basic food prices: ‘Dad would be proud to see his work used in such a way,’ his daughter Rhianna said.

The basket of goods used to measure inflation changes over time: in 1947, it included rabbit, corsets and mangles; in 1970, it featured a keg of stout and terylene slacks. In recent years, additions have included gin, bicycle helmets and jigsaws. Monroe’s basket, however, might more accurately capture real life in our own Interesting Times.