 As demand for luxury goods and beauty products declines in some regions, so have the fortunes of a clutch of the world's richest people. The drop has toppled Bernard Arnault, founder of handbags to champagne conglomerate LVMH, from his number one perch on the Bloomberg Billionaires Index. And in a further sign of more frugal times, the heiress of cosmetics giant L'Oreal, Francois Bettencourt Myers, briefly lost her crown earlier this month,