Introduces theories of aggregate economic activity including the determination of income, employment, and prices; economic growth; and fluctuations. Macroeconomic policies are explored in both closed and open economy models. ECON 3070 and 3080 may be taken in any order; there is no recommended sequence. Prereqs., ECON 1000 or 2020; and either ECON 1078 and 1088, or MATH 1300, or MATH 1310, or MATH 1081, or MATH 1080, 1090, and 1100, or APPM 1350, or equivalent. Prerequisites: Restricted to students with 27-180 credits (Sophomore, Junior or Senior) only.