Trends in the Income of Working-Age People with Disabilities: 1980-2004 Robert Weathers Mathematica Policy Research
Overview • Disability and income measurement • Data sources and income estimates • Comparisons across datasets • Tracking progress using long-term trends
Disability Measurement • Disability Concepts • Sensory; Physical; Mental; ADLs; IADLs; Work Limitations • Multiple dimensions to disability measurement • Environment • Duration • Severity • Differences across national data in disability measurement
Income Measurement • Sharing unit: person, family, household • Family income used to measure poverty and to determine eligibility for many means-tested programs • Household income used in annual Census Bureau report. • Equivalence scales designed to account for sharing within the household and facilitate economic-well being comparisons. In this presentation, we use method suggested by Patricia Ruggles (e=0.5). • Survey measures of income • Detailed questions on income sources aggregated at individual level and then to family level (e.g., ACS, CPS, SIPP) • Single question on family income amounts (e.g., NHIS) • Differences across datasets in measurement of income
Data Sources • American Community Survey (ACS) • 8 individual level income questions aggregated. • Current Population Survey (CPS) • 18 individual level income questions aggregated. • National Health Interview Survey (NHIS) • Yes/No questions about sources (“cues”), 1 question about amount of family income. • Survey of Income and Program Participation (SIPP)
American Community Survey • Sources of Income based on 8 separate questions. • wage or salary income; • net self-employment income; • interest, dividends, or net rental or royalty income or income from estates and trusts; • Social Security or railroad retirement income; • Supplemental Security Income (SSI); • public assistance or welfare payments; • retirement, survivor, or disability pensions; • and all other income (e.g., VA benefits, UI compensation, child support, alimony). • Measures • Individual Income, Family Income, Household Income.
Notes: • ACS, NHIS, SIPP based upon at least one of the following: employment disability, IADL, ADL, mental impairment, physical impairment, or sensory impairment. • CPS based upon employment disability.
Summary of Comparisons • Differences in income across types of disability and differences in income within types of disability across datasets. • Consistent findings: • Low incomes: Persons with mental impairments and limitations performing ADLs, IADLs or employment have lowest levels of income. • Not as low incomes: Persons with limitations that include: severe vision loss, severe hearing loss, and physical functioning.
Long-Term Trends: CPS • Analysis of long-term trends is critical to examining economic progress. • CPS is the only dataset that contains a consistently measure of income from 1979-2005 for the subset of persons with disabilities who report a “work limitation” • Use the data to compare trends in income for persons with and without disabilities.
Summary • Differences across surveys due to differences in definition of disability but also related to differences in income measurement. • ACS strikes a good balance between definition of disability and income measurement, but is relatively new and has limited time series. • CPS only survey that is able to examine long term trends in income, but limited to work limitation measure of disability.
Future Research Questions • As more years of ACS data become available, how do trends in income compare across different definitions of disability and to the CPS work limitation measure? • Is income under-reported in surveys and has income under-reporting in surveys increased over time? • Meyer and Sullivan (2003): Yes, for low-income households. Propose including data on consumption and income to improve measures of income. • Implications for examining income trends for persons with disabilities not well known.
FutureResearch (cont’d) • Can “one question” family income measures be improved? • NHIS, BRFSS and other surveys that collect data on health and disability use one question to measure family income. • Researchers have shown that these measures understate income compared to aggregated measures in the CPS, ACS, MEPS, etc. (Davern et al., 2005) • They propose using methods that combine data across national datasets to improve estimates of income based upon single question. • Need to be aware of the benefits and limitations of these approaches.
References Devern, Michael et al. 2005. “The effect of income question design in health surveys on family income, poverty, and eligibility estimates.” Health Services Research, volume 40(5). Meyer, Bruce D., James X. Sullivan. 2003. “Measuring the well-being of the poor using data on income and consumption.” Journal of Human Resources, volume 38 supplement.