This isn't an actual survey of people though. Cornell is saying "The living wage for this county is $xx,000, and xx% of people make less than $xx,000 in this co

This isn't an actual survey of people though. Cornell is saying "The living wage for this county is $xx,000, and xx% of people make less than $xx,000 in this county." They're comparing a range of incomes against essentially the fixed median cost of living.