Foreign exchange: macro puzzles, micro tools

This paper reviews recent progress in applying information-theoretic tools to long-standing exchange rate puzzles. I begin by distinguishing the traditional public information approach (e.g. monetary models, including new open economy models) from the newer dispersed information approach. (The latter focuses on how information is aggregated in the trading process.) I then review empirical results from the dispersed information approach and relate them to two key puzzles, the determination puzzle and the excess volatility puzzle. The dispersed information approach has made progress on both.