# SO5032: Lab Materials

## Table of Contents

## 1 Week 9 Lab

### 1.1 Logistic Regression

This file contains Stata code to run the credit card example in A&F:

do http://teaching.sociology.ul.ie/so5032/creditcard.do

Execute the code to create the working data file, and examine the
relationship between having a credit card and income (compare means,
group income and cross tabulate, etc.). The variable `card`

records
whether a credit card is held, and `income`

is the explanatory variable.

Now fit the linear probability model and interpret it:

reg card income

Save the predicted values:

predict plin

Now fit the logistic regression, and interpret it:

logit card income

Save the predicted values and graph them against income.

predict plog scatter care plog income

Compare this graph with that relating the first model's predicted values to income:

scatter care plog plin income

#### 1.1.1 Predicted values by hand

Calculate predicted values by hand (log-odds, odds and probabilities) for income = 10, 11, 60, and 61.

#### 1.1.2 Age and health

Repeat the exercise with this alternative data file:

do http://teaching.sociology.ul.ie/so5032/labs/limit.do

which has data on age and whether the respondent finds their health limits their daily activities.