An expected writeoff by the Royal Bank of Scotland (RBS) is further evidence that acquisitions are an inexact science. It is believed that RBS will announce a £4 billion ($6.2 billion) writeoff related to its acquisition of Citizens Financial. The writeoff will almost entirely erase the company's 2014 profit. RBS has already sold 29 percent of Citizens Financial in a public offering, and plans to sell more of the company. RBS purchased Citizens for $130 billion in 1988, but the current market capitalization of Citizens is a much smaller $13.7 billion.