pol 51 lecture 11

pol 51 lecture 11 - y-intercept parameter <- a...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Pol 51 Lecture 11 U i is stochastic, “random” unexplained. Unexplained because people are complicated, we can’t always explain human behavior. OUR THEORIES ARE ALWAYS WRONG. All models are wrong but some are useful. Something about the population so our model: Y i = a + bX i <- systematic But we must consider u i . rewritten as a + bX i + u i Whenever there is a carrot on top of the variables then it is an estimate.
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: y-intercept parameter &lt;- a slope parameter &lt;- b so Yi and Xi are values that are measured rather than estimated. We use these to estimate a, b, and u. why do we care about the predicted if we have the observed? The Ui tells us a lot of stuff. It tells us how well the line fits the data. You want the sum of square residuals to be close to 0. What does this tell us about politics?...
View Full Document

This note was uploaded on 08/30/2011 for the course POL 51 taught by Professor Ryan,john during the Summer '08 term at UC Davis.

Ask a homework question - tutors are online