An important determinant of the approach you will use to measure SES and SSS is the level at which you plan to assess its effects — the societal level, the community or neighborhood level, or the individual level. If you are examining how a new policy affected the number of individuals living in poverty, you may look into how many people are living below federal poverty thresholds before and after it takes effect. Researchers interested in how living in a particular neighborhood affects diagnoses of a particular illness may examine the median income of individuals living in that community. Others interested in how SES or SSS affects an individual's mental health may assess occupational prestige or educational attainment.
Education can be measured using continuous variables (e.g., highest year of school completed) or categorical variables (e.g., 1-6 scale indicating the highest grade completed). Higher levels of education are often associated with better economic outcomes, as well as the expansion of social resources (APA, 2007).
Income can be measured in a variety of ways, including family income, assessments of wealth and subjective assessments of economic pressure. At the neighborhood and societal level, federal poverty thresholds, supplemental poverty measures and school and neighborhood level indicators of poverty can be assessed. Lack of income has been found to be related to poorer health, mainly due to reduced access to goods and services (such as health care) that can be beneficial to health (APA, 2007).
Occupation can be assessed by asking participants to note their current or most recent occupation or job title, or to indicate their occupational category from a list. Aside from financial benefits, employment can improve one's physical and mental health and expand social networks (APA, 2007). However, the nature of lower SES positions can undermine these benefits, as the job itself may be hazardous or monotonous (APA, 2007).
The National Committee on Vital and Health Statistics has provided recommendations (PDF, 67KB) for measuring education, income, employment and family size/relationships. This provides researchers and policy makers with a consistent, standardized measurement and collection approach to SES across groups.
Education should be measured in single years completed up to 5 or more years of college, and should also include collection of information on whether the individual obtained a high school diploma or equivalent. Surveys should also collect information on degree attainment.
Income should be asked for the individual survey respondent and for the respondent's entire family, as well as household income. The collection of income should include the measurement of total income, earned or unearned, from specific sources (e.g., wages and salaries, dividends and interest, Social Security, unemployment insurance, disability income, etc.)
Occupation should be measured at a minimum by a set of two standardized questions: one question to collect occupation and one question to collect industry. Additional information about work tasks and employer should also be considered.
Given that family size and household composition are required to calculate poverty, and survey measures should collect information on family size and household composition in compliance with official federal poverty guidelines as issued and published each year.
For psychologists and other researchers who are interested in a more nuanced approach to measuring SES and SSS, an article by Diemer, Mistry, Wadsworth, Lopez and Reimers (2013) provides an in-depth look at best practices for conceptualizing and measuring social class. Specifically, the authors provide recommendations for the following areas: