Topics: Economics and Personal Finances, Socioeconomic Class. 1  Richard Fry is a senior researcher focusing on economics and education at Pew Research Center. 2  Rakesh Kochhar is an associate director of research at Pew Research Center.
In the United States, the Census Bureau determines who is poor using an economic poverty measure, by calculating official poverty estimates using a set of dollar-value thresholds, or minimum amount of income needed to meet basic needs, that vary by family size and composition.
Elasticity is a measure of responsiveness. The responsiveness of behavior measured by variable Z to a change in environment variable Y is the change in Z observed in response to a change in Y. Specifically, this approximation is common: elasticity = (percentage change in Z) / (percentage change in Y). The smaller the percentage change in Y is practical, the better the measure is and the closer it is to the intended theoretically perfect measure..