MIT: Veronica Guerrieri's "Principles of Macroeconomics, L5-L7: The Demand Side of the Economy"

Read these lecture notes, which will provide an introduction to two important expenditure components of the GDP. This reading will also prepare you for further exposure to other macroeconomic variable, which you will study in the remainder of this course. Note that consumption is the largest expenditure component and investment is the most volatile expenditure component.