Loading [MathJax]/extensions/TeX/boldsymbol.js

 

 

 

Linear classifier

Before moving to the logistic model, let us try to use our linear regression model to classify these two outcomes. We could for example fit a linear model to the default case if y_i > 0.5 and the no default case y_i \leq 0.5 .

We would then have our weighted linear combination, namely

\begin{equation} \boldsymbol{y} = \boldsymbol{X}^T\boldsymbol{\beta} + \boldsymbol{\epsilon}, \tag{1} \end{equation}

where \boldsymbol{y} is a vector representing the possible outcomes, \boldsymbol{X} is our n\times p design matrix and \boldsymbol{\beta} represents our estimators/predictors.