Income deficit is the difference between a single person or family's income and its poverty threshold or poverty line, when the former is exceeded by the latter. Data on the income deficits of various members of a population allow for the construction of one type of measurement of income inequality in that population. Individuals or families that fall below the line are considered to be in poverty whereas families that fall above are not. The income deficit is one of two measures that are used to determine a person or family's income distance from the poverty threshold,the other being a ratio rather than a difference.