Study Design

Child Development Supplement (CDS)

Original CDS (CDS I-III, 1997-2007)

CDS began in 1997 with 3,653 children aged 0 to 12 years. Up to two children were randomly sampled from eligible families, enabling sibling comparisons. Children under 18 years and their caregivers were re-interviewed in up to two additional waves in 2002 (CDS-II) and 2007 (CDS-III).

At each wave, primary caregivers of children (usually a parent or other relative) and older children themselves provided detailed information about children’s well-being and development in their family, school, and neighborhood context. See the text box below for topics and domains covered in CDS interviews and assessments.

Ongoing CDS

CDS has transitioned from a cohort design to an ongoing panel design. Since 2014, CDS has collected information every five years about all eligible minor children in PSID. The ongoing CDS includes children from a previous wave and those who have been born or moved into an eligible family since the last wave.

The 2014 Child Development Supplement (N=4,333) was the first wave collected under this new design and gathered information on PSID children born between 1997 and 2013 (age 1-17 years at interview). CDS-2014 creates new opportunities to investigate issues of research and policy relevance concerning today’s children as well as to compare their outcomes and circumstances to those of the preceding generation of children in CDS I-III.

The 2019 Child Development Supplement will be the next available wave in this steady-state design. It will include information on all children age 0-17 years, including children who were born since 2014 or who were recently added to PSID as part of the new immigrant refresher sample.

Contents of the CDS Interview

• Interviews with caregivers and older children
• Caregiver and child standardized assessments of achievement
• Child time diaries for one weekday and one weekend day
• Height, weight, and body mass index for children and caregivers
• Linkages to neighborhood geocodes and school identifiers (restricted-use)
• Repeated observations over up to three waves covering entire childhood

· Forthcoming from CDS-2014: Genomic data and polygenic risk scores for children age 5-17 and primary caregivers

Transition into Adulthood Supplement (TAS)

Since 2005, TAS has collected information on transitions in schooling, work, and family formation during early adulthood and about young adults’ expectations, attitudes, health, and psychosocial well-being. See the text box below for a list of topics covered in the TAS interview.

Through 2015, the TAS sample followed children from CDS-I as they transitioned into young adulthood through age 28. Since 2017, TAS includes all eligible young adults aged 18-28 years living in PSID households regardless of prior CDS or Main PSID participation.

Together, the study design of CDS and TAS enables longitudinal, cross-sectional, and cohort-comparative analysis of child and young adult development and well-being in an ongoing, nationally-representative US sample.

Contents of the TAS Interview

• Biennial interviews with young adults for up to five waves
• Content includes education, employment, relationships, attitudes, health, and health behaviors
• Linkages to neighborhood geocodes and college identifiers (restricted-use)
• Linkable to extensive data on childhood circumstances from CDS and Main PSID
• TAS respondents continue to be followed after age 28 through the Main PSID

Embedded in the world’s longest-running household panel study

CDS and TAS are embedded in the Panel Study of Income Dynamics (PSID), the world’s longest-running nationally representative household panel survey. With over 50 years of information collected from the same families and their descendants, PSID is a cornerstone of the US data infrastructure for empirically based social science research.

Annually between 1968 and 1997 and biennially since then, PSID has collected data on individuals and families that emphasize the dynamic and interactive aspects of family economics, demography, and health. When paired with CDS and TAS, the design and content of PSID enable research on the intergenerational influence of family on child and young adult outcomes and on how childhood and young adulthood shape later health and well-being.

When young adults establish their own households, they become eligible to participate in the biennial PSID interview. Young adults who set up their own households are eligible for both TAS and PSID until age 28.

Note that children and young adults are only observed in CDS or TAS in a given wave if their family participated in the immediately prior wave of the PSID interview.

Following individuals over time in CDS, TAS, and PSID

The young people included in CDS and TAS are descendants of sample members from the earliest wave of PSID in 1968 or sample members from PSID's immigrant refresher in 1997 or 2017. When CDS and TAS respondents reach adulthood and establish their own households, they are eligible to become PSID participants themselves. Over time, CDS, TAS, and PSID have the potential to cover the life course of individuals from early childhood through late adulthood.

This grid describes the age range for eligible children or young adults in each wave of CDS and TAS and the years in which each wave of data collection occurred.

The Original CDS and TAS Cohorts

The Child Development Supplement began in 1997 (dark blue bars) as a cohort study. Children born between 1984 and 1997 who were between 0 and 12 years old in 1997 were eligible for CDS-I. Up to two age-eligible children per family were selected to participate. CDS-II revisited study participants in 2002-03, when they were between 5 and 17 years old. In 2007, the third and final wave of the original cohort study was conducted with children who were between 10 and 17 years old.

The oldest members of the original CDS cohort had entered adulthood by 2003 and were ineligible for CDS-III. Instead, they were included in the earliest waves of the Transition into Adulthood Supplement.

The biennial Transition into Adulthood Supplement (TAS, green bars) began in 2005 to follow CDS participants as they entered adulthood. The first wave included 745 participants who were between 18 and 20 years old. Each subsequent wave included interviews with previous respondents and added CDS participants who had entered adulthood in the preceding two years. By 2013, TAS included respondents who were between 18 and 28 years old.

Year of birth determines the waves in which a youth in the original CDS cohort was observed in in CDS or TAS. In the grid, cells marked with an asterisk (*) plot the course of a child born in 1996 who was observed at age 1 year in the first wave of CDS in 1997 (CDS-I), at age 6 years in CDS-II (2002), and at age 11 years in CDS-III (2007). The child was first eligible to appear in TAS in 2015 at age 19 years.

Ongoing CDS and TAS

All members of the original CDS cohort had entered adulthood by 2014. In that year, children in active PSID families who were born since 1997 were invited to participate in a new, ongoing CDS (lighter blue bar). Unlike the original CDS cohort, which included up to two children age 0-12 years per family, the new, ongoing CDS included all children age 0-17 years (N=4,333).

Under the new CDS design, children 17 years and younger and their families will be invited to participate in a CDS interview about every 5 years. Sample children who have been born or moved into a CDS family since the last wave of CDS will be eligible to participate. This approach was used for the first time in CDS in 2019 (data not yet in public release).

Since 2017, TAS has also adopted a more expansive, steady-state design. The biennial TAS interview now includes all eligible young adults age 18-28 years in active PSID families regardless of whether they had ever participated in CDS. This expansion adds young adults who were eligible for but not selected for the original CDS cohort; whose families declined to participate in the original or ongoing CDS studies; or who entered PSID after 1997, including young adults whose families joined through the 2017 immigrant refresher. (Young adults in the latter group are observed in TAS for the first time in 2019.)

Studying primary caregivers of children

The primary caregiver is the adult who has primary responsibility for caring for CDS children, usually a parent or other relative. At each wave of CDS, primary caregivers provide information about themselves, their household, and each participating child. The CDS-TAS data center supports data downloads to study the primary caregiver as a unit of analysis.

In some families, children in the original CDS cohort are now primary caregivers to children in the new, ongoing CDS. This feature of the multi-cohort design of CDS offers a unique opportunity to follow today’s parents and caregivers prospectively from childhood.