The definitions of poverty are used to measure relative wealth, not whether someone lives paycheck to paycheck. As income increases, paycheck to paycheck reports decrease, but at a certain point it then increases again. Living paycheck to paycheck is a poor measure, because you can buy a house that’s too expensive for your income, or a car, eat out too much, or make a variety of other poor life choices. That’s why the poverty index is good at measuring relative decreases in poverty because it ignores poor life choices.