POL222H1 Lecture 9: pol222 - 9
Document Summary
Basic of linear regression: what is linear regression, mathematical interpretation, substantive interpretation. Linear regression examples: economic voting in canada, economic voting in u. s. presidential elections. If x and z take only a small number of values, we may divide our observations into groups with the same value of x and z: however, x and z may take many different values. Then the simple divide & compare method no longer work we need a generalization of divide & compare. Relationship between x and y: x takes two values only: x = 0 or x=1. Divide our data by different values of x: calculate the average of y for each value of x (conditional. Average): how y would vary on average as x changes, x takes multiple discrete values: x = 0, 1, 2, 3, divide our data by different values of x. Calculate the average of y for each value of x (conditional.
