The NLSY97 survey collects a large amount of detailed information on the income of respondents, including income from participation in government transfer programs for low-income individuals and families. At particular ages, or after achieving independence status in earlier rounds, youths also answer questions on their assets and debts. In addition, information is available for other members of the household (see Household Composition and Parent Characteristics.) Table 1 summarizes the NLSY97 topics any global universe restrictions available in this section.
| NLSY97 User's Guide Topics | Rounds 1-3 Universe | Rounds 4-8 Universe | Round 9 and up Universe |
|---|---|---|---|
| Assets & Debt Details on respondent's asset holdings (real estate, businesses, vehicles) and amount of debt owed; net worth |
all ages; independent | independent or turned 18 or 20 years old since last interview | Assets 20 section asked of those who turned 20 since last interview; Assets 25 section administered to respondents in their first interview during or after calendar year in which they reached age 25; Assets 30 section administered to those respondents in their first interview during or after year they reached age 30; Assets 35 section administrated in first interview during or after year respondents reach age 35; Assets 40 section administrated in first interview during or after year respondents reach age 40. |
| Income Gross wage/salary data for respondent, along with data on other income sources (rental property, inheritance, child support, annuities) |
all ages | all ages | all ages |
| Program Participation Provides details on respondent's enrollment/participation in government programs such as TANF, food stamps, unemployment, WIC, Worker's Compensation |
all ages; independent | all ages; independent | all ages |
| Note: See independence criteria. | |||
Important Information: Using income and asset data
- Income and assets questions can be cognitively difficult or feel intrusive to respondents. To reduce the proportion of missing ("don't know" or "refused") data, respondents who do not provide exact dollar answers to questions are asked follow-up questions designed to elicit approximate information. For many income categories, these respondents are asked to select the applicable category from a predefined list of ranges. The approach for assets questions is slightly different: The initial question asks the respondent to provide an exact value, but if s/he is unable or unwilling to do so, interviewers are instructed to ask the respondent to define a range for the value using whatever values s/he feels are appropriate. If the respondent doesn't know or refuses to provide either an exact value or a range, a follow-up question asks him or her to select the appropriate range from a predefined list. This will provide researchers with some information on income, asset, and debt amounts when the respondent is reluctant or unable to furnish an exact figure.
- Topcoding: To protect the confidentiality of respondents, the survey "topcodes" the highest income and asset values. In each survey round, income and asset variables that include high values are identified for topcoding. (For example, the wage and salary income variable is usually topcoded, but variables indicating the amount received from public assistance programs are not.) For income variables, the top 2 percent of reported values are topcoded and replaced with the mean of the high values. Asset variables have predefined cut-off points for topcoding depending on the variable type. Calculating topcode values in this way allows statistics such as means to accurately reflect the status of the population under examination without violating respondent privacy. Notes in the codeblocks (variable-specific information accessed through NLS Investigator) for topcoded income and asset variables provide more information about the exact calculations used to topcode each variable.
Independence criteria
Historically, NLSY97 youths were considered independent if they have had a child, were enrolled in a 4-year college, were no longer enrolled in school, were not living with any parents or parent-figures, or had ever been married or were in a marriage-like relationship (defined in rounds 1-8 as a sexual relationship in which partners of the opposite sex live together) at the time of the survey. Reaching the age of 18 was another criteria for independence, but the reference date for that age varied between surveys and questionnaire sections. Figure 1 contains more details. All NLSY97 respondents are now considered independent. Note: YINC-400 is the check for independence.
Figure 1. NLSY97 independence criteria
| Survey | Income and Program Participation | Assets |
|---|---|---|
| Round 1 | No youths age 18 | No youths age 18 |
| Round 2 | No youths age 18 | No youths age 18 |
| Round 3 | 1980 birth cohort eligible (age 18 as of 12/31/1998) | 1980 birth cohort eligible (age 18 as of 12/31/1998) |
| Round 4 | 1981 birth cohort eligible (age 18 as of 12/31/1999) | Eligible if age 18 as of interview date |
| Round 5 | 1982 birth cohort eligible (age 18 as of 12/31/2000) | Eligible if age 18 as of interview date |
| Round 6 | 1983 birth cohort eligible (age 18 as of 12/31/2001) | Eligible if age 18 as of interview date |
| Round 7 | All cohorts eligible | Eligible if age 18 as of interview date |
| Round 8 and up | All cohorts eligible | All cohorts eligible |
Other criteria
All rounds, regardless of age: The youth is independent if he or she has had a child, is enrolled in a 4-year college, is no longer enrolled in school, is not living with any parents or parent-figures, or has ever been married or is in a marriage-like relationship at the time of the survey. A "marriage-like relationship" is defined in rounds 1-8 as a sexual relationship where partners of the opposite sex live together.
Note: Starting with round 5, the assets questions were administered to respondents during the first interview after they turned 18 and the first interview after they turned 20. Assets questions were also administered in the survey year where all members of that birth cohort would turn 25 and again when they would turn 30, 35 and 40.