# Logistic regression

USE: When your dependent variable is categorical. Your independent variable can have any measurement.

SYNTAX: LOGISTIC REGRESSION dependent WITH independent.

**b0**: the log odds for the category 1 of the dependent variable when the independent variable’s category is 0

**b1**: how much larger or smaller the log odds becomes as the independent variable increases by 1 unit.

**b0+b1**: the log odds for the category 1 of the dependent variable when the independent variable’s category is 1.

**b1 coefficient > 0** -> a 1 unit increase in X increases the likelihood/probability that y=1 This means that an increase in X makes the outcome of 1 more likely.

**b1 coefficient < 0** -> a 1 unit increase in X decreases the likelihood/probability that y=1. This means that an increase in X makes the outcome of 1 less likely.

**Exp(B): < 1** -> we say „as low as” : a 1 unit increase in X decreases the likelihood/probability that y=1. This means that an increase in X makes the outcome of 1 less likely. It indicates a negative effect.

**Exp(B): > 1** -> we say „as high as” a 1 unit increase in X increases the likelihood/probability that y=1 This means that an increase in X makes the outcome of 1 more likely. It indicates a positive effect.

**Exp(B)=1** -> no effect

We interpret **the sign** of the coefficient, not the magnitude! The magnitude cannot be interpreted using the coefficient because the different models have different scales of coefficients.