If February’s merger agreement between American Airlines and U.S. Airways sparked a sense of déjà vu, that may be because it would create the seventh major airline coupling since 2005. Or because a similar pattern seems to be cropping up in most industries today, with fewer players holding more of the cards. As a result, it can seem as if we are growing accustomed to monopoly. Is this the natural evolution of a consumer-oriented market, or should we be worried?