8.4 Closing paths

A path is Open if all of the variables along that path have variation in the data

So we close a patch by

• Picking a specific data set (e.g., no drug users)
• Adding a variable on the path as control variable (ch 13)
• Matching (ch 14)

If we can control for at least one variable on each of our Bad Paths without controlling for anything on one of our Good Paths, we have identified the answer to our research question.

controlling for income

controlling for income and health