# Explanatory and Response Variables

An **explanatory variable** is one variable in a pair of variables which we suspect affects the other. Labeling a variable as explanatory of another variable does not guarantee the relationship between the two is actually causal. It is merely a label so we can keep track of which variables we suspect affects the other.

In a pair of variables, where one is an **explanatory variable**, the other is the **response variable**.

One could say that an **explanatory variable** *might affect* a **response variable**.