Another zombie statistic doing the rounds.

A price war is currently raging between the major supermarkets and one of the key weapons is milk, something everyone (except politicians, it seems) knows the price of. As a result, most stores are doing a massive loss-leader on one particular item: a four-pint bottle. Many of the big supermarkets are selling this staple of family life for £1 - eg, 25p per pint. But the discounters, like Lidl and Aldi, are selling it for 89p - and now Asda has decided to follow suit.

As ever, many dairy farmers are struggling to operate profitably and are linking this price war to the price they receive for their product, which seems a bit dubious. Milk, as a commodity product, has always been very keenly priced. But even worse is the claim that ‘milk is now cheaper than water’ in supermarkets. A brief comparison, even in a small Tesco Express, suggests this is nonsense. A four-pint (2.27 litre) bottle of own-brand milk is £1, or 44p per litre. A two-litre bottle of Tesco Ashbeck mineral water (not on any kind of loss-leading special offer) is 47p - or 23.5p per litre. Even at the price other supermarkets are selling milk (89p per bottle or 39p per litre), water is still considerably cheaper.

Of course, supermarkets have all sorts of weird and wonderful pricing strategies based on item sizes and branding, so it’s perfectly possible to find water in a form in the supermarket that is more expensive than the massively discounted large carton of milk. But the nearest like-for-like comparison suggests milk is still reassuringly much more expensive than water.

And while we’re on the subject of zombie statistics, at 23.5p per litre, water is also a hell of a lot cheaper than petrol…