That sentence confused me, too, but it's clarified in the next paragraph:

> Children who grow up with high economic connectedness earn 20 percent more as adults on average than otherwise similar children who do not, a gap equal to growing up in a family making 47,000 dollars a year instead of 27,000.

ie: knowing wealthier people has as much impact on your income as growing up in a family making $47k/year instead of $27k/year