- A proxy variable is a measurable variable that isn't directly relevant but is used in place of another unobservable or immeasurable variable.
- Proxy variables interact with other proxy variables.
- It's dangerous focusing only on one proxy variable.
- To work with multiple proxy variables, you must express them in the same unit of measure.
- A good proxy variable must have a closer correlation with the variable of interest.
- Proxy variable per-capita GDP measures standard of living or quality of life.
- Changes in height over a fixed time are a proxy for hormone levels in the blood.
- [Slack](/zettel/slack-and-efficiency) can be used to represent an economic impact on a project.
- What are other types of proxy variables?
- [Wikipedia. Proxy (statistics)](<https://en.wikipedia.org/wiki/Proxy_(statistics)>)