Rebecca Armstrong: Can a quick slick of lipstick make business boom? It seems as though two of the country's biggest retailers have decided to put their faith in lipstick economics. The theory of the "lipstick index" was originally dreamt up by Leonard Lauder, chairman of Estee Lauder Companies after the attacks of 9/11 saw America's consumer spending falter. Lauder noticed that despite the downturn, his company was seeing lipsticks fly off the shelves. Because, he reasoned, in troubled times, women are more likely to make small, feel-good purchases that are cheap but boost their moods. Since then, the phrase has become common currency, even if some economists have disputed Lauder's findings (and many women have become sick to death of their vast purchasing power being boiled down to cosmetic splurges rather than, say, investments in automobiles, appliances and holidays). Anyway, both John Lewis and Marks & Spencer have opened new beauty departments this month, each with their own spin on pushing powder and paint. John Lewis has transformed the ground floor of its Oxford Street branch into a beauty department that has what seems like every premium brand under the sun. It has 12,000 sq ft of make-up counters, perfume displays, threading bars and perfectly polished sales- people eager to help. So eager, in fact, that when I visited last week, I had to keep up a brisk pace to avoid being spritzed or spruced. According to industry bible Retail Week, John Lewis intends this temple of cosmetic enhancement to be up there with Selfridges, Harrods and Macy's in New York. We'll have to see whether the more traditional John Lewis customer en route to the school shoes or haberdashery department will be snapping up the £15,000 bottle of perfume on sale. M&S has gone for something different. Last week it unveiled its first in-store Your Beauty department in London's Kensington, and it will follow this with 100 more across the country, in Manchester, Aberdeen, Belfast, Newcastle and Exeter, among others - much more than a one-town wonder. Own-brand products predominate, although, as with its food halls, carefully picked brands are also on sale. Mineral make-up alongside a three-pack of pants? Frances Russell, trading director of beauty and lingerie, is keenly aware that, whether you buy into the lipstick economics theory or not, affordability is key. There are "affordable brands, starting from £2, through to higher end brands, such as Fragonard, Nuxe and Filorga. We aim to offer the customer really good value. If we really are all buying warpaint to cover up our recession blues, perhaps there's room for value as well as a bit of va-va-voom.