This is the second course in the four-quarter graduate sequence in macroeconomics. Its purpose is to introduce the basic models macroeconomists use to study fluctuations. The course is organized around nine topics/sections: Fluctuations and Facts; The basic model: the consumption/saving choice; Allowing for a labor/leisure choice (the RBC model); Allowing for non trivial investment decisions; Allowing for two goods; Introducing money; Introducing price setting; Introducing staggering of price decisions; and Applications to fiscal and monetary policy.