Louis Vuitton remained the most valuable brand in 2014, according to an annual study by Millward Brown and WPP. Its value actually increased by 6 percent to $27.45 billion. Hermès came next, and strangely, in spite of the positive results reported by its owners, its value declined by 13 percent to $18.9 billion. It was followed by Gucci, down by 14 percent to $13.8 billion. Among the other brands, Chanel improved by 15 percent and Prada lost 35 percent of its value.