The Fragile Families and Child Wellbeing Study
and Fragile Families Challenge

The Fragile Families and Child Wellbeing Study

The Fragile Families and Child Wellbeing Study (FFCWS) follows a cohort of nearly 5,000 children born in the U.S. between 1998 and 2000. The study oversampled births to unmarried couples; and, when weighted, the data are representative of births in large U.S. cities at the turn of the century.

The FFCWS was originally designed to address four questions of great interest to researchers and policy makers: (1) What are the conditions and capabilities of unmarried parents, especially fathers?; (2) What is the nature of the relationships between unmarried parents?; (3) How do children born into these families fare?; and (4) How do policies and environmental conditions affect families and children?

The FFCWS consists of interviews with mothers, fathers, and/or primary caregivers at birth and again when children are ages one, three, five, nine, and fifteen. The parent interviews collected information on attitudes, relationships, parenting behavior, demographic characteristics, health (mental and physical), economic and employment status, neighborhood characteristics, and program participation. At ages nine and fifteen, children were interviewed directly (either during the home visit or on the telephone). The direct child interviews collected data on family relationships, home routines, schools, peers, and physical and mental health, as well as health behaviors.

A collaborative study of the FFCWS, the In-Home Longitudinal Study of Pre-School Aged Children (In-Home Study) collected data from a subset of the FFCWS Core respondents at the Year 3 and 5 follow-ups to ask how parental resources in the form of parental presence or absence, time, and money influence children under the age of five. The In-Home Study collected information on a variety of domains of the child's environment, including: the physical environment (quality of housing, nutrition and food security, health care, adequacy of clothing and supervision) and parenting (parental discipline, parental attachment, and cognitive stimulation). In addition, the In-Home Study also collected information on several important child outcomes, including anthropometrics, child behaviors, and cognitive ability. This information was collected through: interviews with the child's primary caregiver, and direct observation of the child's home environment and the child's interactions with his or her caregiver. Similar activities were conducted during the Year 9 follow-up. At the Year 15 follow-up, a condensed set of home visit activities were conducted with a subsample of approximately 1,000 teens.

An additional collaborative study collected data from the child care provider (Year 3) and teacher (Years 9 and 15) through mail-based surveys.

Previously, FFCWS data were provided by sub-study. As of the Fall 2018 Re-release, all FFCWS data are now provided in one merged file (all waves) and in individual files by wave. The wave-specific files contain all data from that wave of data collection, including weights and data collected in the collaborative surveys. The Re-release also includes a number of other updates incuding standardization of variable names, standardization of negative codes, newly released data and weights, and updates to previously released data. Please see the release memo for further details.

In January 2020, the FFCWS data were re-released to include nine additional variables (t4b1a-t4b1i). These variables were incorrectly dropped from the previously released files due to a coding error in the Fall 2018 standardization work.

Documentation for these files is available on the FFCWS website located at https://fragilefamilies.princeton.edu/. See below for more information about documentation.

Data collection for the Fragile Families and Child Wellbeing Study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) of the National Institutes of Health under award numbers R01HD36916, R01HD39135, and R01HD40421, as well as a consortium of private foundations.

The Fragile Families Challenge

In 2017, a team of researchers affiliated with Princeton University hosted a scientific mass collaboration, which used predictive modeling techniques to predict a set of six outcome variables at children's fifteenth birthdays based on data from the first five waves of the Fragile Families and Child Wellbeing Study. Participants were provided with a special merged version of the study data to be used to develop their models during the collaboration. These Fragile Families Challenge files contain their own unique identifier for each family in the study, and were constructed specifically for use during this project. These files should be downloaded in order to extend or replicate the work from the Fragile Families Challenge, but should not be merged with the Fragile Families and Child Wellbeing Study data files for new analyses.

The Fragile Families Challenge was supported by a grant from the Russell Sage Foundation.


Please visit the FFCWS website to download the documentation and find out more about study and data files including:

  • Public Data User Guides for each wave
  • Questionnaires for all waves
  • Sample design paper and weighting documentation
  • Metadata Explorer (NEW FALL 2018)
  • Data alerts and frequently asked questions (FAQ)
  • Review publications and working papers using the FFCWS data
  • Latest FFCWS News (data workshops, recent publications, press)

For those researchers specifically interested in extending and replicating work in the Fragile Families Challenge, the Fragile Families Challenge blog also provides additional information.

Contact Us

If you have any questions about the FFCWS or problems obtaining or using the data, please email us at ffdata@princeton.edu.

Registration Required

To access these datasets, please login or register as a user of the data archive.