Imagine if you live in a university town, but it just gets redistricted to include a neighboring industrial town. The life expectancy of your town just dropped

Imagine if you live in a university town, but it just gets redistricted to include a neighboring industrial town. The life expectancy of your town just dropped, drastically. But does that change your life at all? No, your life is exactly the same as before. Same with these stats. Just because people who have lower life expectancies move or happen to live near you, it doesn't change anything about your life. If canada and the US merged, the average life expectancy of the new country would go up, but that number itself wouldn't change anyone's life. It's the same with arbitrary county groupings. If you live in a county with lots of poor people, they will have a lower life expectancy. That doesn't mean anything about you, though. If the border was different, you might live in a county with lots of rich people.