European Central Bank staff presented policy makers with models for buying as much as 500 billion euros ($591 billion) of investment-grade assets, according to a person who attended a meeting of the Governing Council. Various quantitative-easing options were shown to governors on Jan. 7 in Frankfurt, including buying only AAA-rated debt or bonds rated at least BBB-, the euro-area central bank official said. Governors took no decision on the design or implementation of any package after the presentation, according to the person and another official who attended the meeting. The people asked not to be identified ... (full story)