Endogenous vs.exogenous variables: The values of endogenous variables are determined in the model. The values of exogenous variables are determined outside the model: the model takes their values behavior as given. In the model of supply demand for cars, endogenous: P,Q°，Q exogenous: Y,P CHAPTER 1 The Science of Macroeconomics slide 22CHAPTER 1 The Science of Macroeconomics slide 22 Endogenous vs. exogenous variables: ▪ The values of endogenous variables are determined in the model. ▪ The values of exogenous variables are determined outside the model: the model takes their values & behavior as given. ▪ In the model of supply & demand for cars, endogenous: , , d s P Q Q exogenous: , Y Ps 3