Supplemental Poverty Measure (SPM): The Supplemental Poverty Measure is an approach to measure poverty that considers the resources a family has available (including non-cash benefits and tax credits) to meet food, clothing, shelter, and utility needs and compares those resources to a threshold that represents modest levels of actual spending by families on those need, plus an additional amount to meet personal hygiene and other very basic needs. The threshold also subtracts work-related (including child care) and medical out-of-pocket expenses, since those expenses are considered obligatory and are not available to meet other needs.
For more information, see: http://www.bls.gov/pir/spmhome.htm
Transfer Income Model Version III (TRIM III): A policy microsimulation model, housed at the Urban Institute, on contract with the U.S. Department of Health and Human Services. For more information on how TRIM was used, see our research methodology.
For more information, see: http://trim3.urban.org/T3Welcome.php
Deep poverty: Living with household income below half of the poverty threshold, as determined by the SPM. Some researchers have suggested, because of the SPM’s comprehensive resource measure and the arguably low threshold, a more appropriate cutoff for deep poverty might be three quarters of the SPM threshold. Accordingly, we include estimates of the rates at both the 50 percent and 75 percent SPM levels.
SPM poverty rate: The share of a population living below 100 percent of the SPM threshold.
SPM poverty rate at 75% of threshold: The share of a population living below 75 percent of the SPM threshold.
SPM Deep Poverty Rate: The share of a population living below 50 percent of the SPM threshold.
Standard Error: A statistical measure that demonstrates how accurately a sample represents a corresponding true population. The standard error indicates how much the sample mean may differ from the true population mean. A normal distribution, or a bell curve, is assumed throughout this analysis, so the standard error is used to estimate confidence intervals (below).
For more information, see:
Confidence interval (CI): Statistics in this analysis are calculated at 95 percent confidence levels. This means, if the same population is sampled on numerous occasions and estimates are made on each occasion, the confidence intervals would bracket the population parameter in approximately 95 percent of the cases. For example, the national deep poverty rate is estimated to be 3.7 percent, with 95 percent confidence intervals of 3.7 percent and 3.8 percent. This means that if the same methodology were used repeatedly, there is a 95 percent chance that that each resulting deep poverty rate estimate would be between 3.7 percent and 3.8 percent.
For more information, see: https://www.census.gov/did/www/saipe/methods/statecounty/ci.html
Geographic adjustment: Adjustments made to the poverty threshold by the Census Bureau to account for geographic price level differences in the prices for goods and services, particularly regarding cost of shelter as measured by rents.
Metropolitan area: An urban centric region designated as a Metropolitan Statistical Area (MSA) by the Office of Management and Budget (OMB). An MSA consists of the county or counties socially and economically integrated with at least one urban core of at least 50,000 population.
Non-metropolitan areas: Regions without at least one urbanized area with a population of 50,000 or more.
The Current Population Survey (CPS): A monthly survey, sponsored by the Bureau of Labor Statistics and conducted by the U.S. Census Bureau, of approximately 60,000 households that offers a nationally representative, multistage, stratified sample of the United States noninstitutionalized population. Detailed labor market and demographic data are collected on all respondents aged 16 years and older.