Data and documentation

Data publicly available


Currently in progress



data collection

July 2018 - June 2019

Age 1 

data collection

July 2019- June 2020

Age 2

data collection

July 2020- June 2021

Age 3

data collection

July 2021- June 2022






Hypothesis preregistered with

Revised set of hypotheses submitted, before age 1 data collection

Revised set of hypotheses submitted, before age 2 data collection

Baby’s First Years data are freely available to the research community through the Interuniversity Consortium for Political and Social Research (ICPSR).  Data from each BFY data collection wave are released as soon as they are cleaned and documented. 

BFY Baseline Data Summary (collected at birth)

Between May 2018 and June, 2019, 1,050 mothers with incomes below the poverty threshold in four metropolitan areas in the United States were recruited in 12 hospitals shortly after giving birth and completed a baseline interview. Some 1,000 of these 1,050 agreed to receive the cash gift that the study offered. The User Guide for the BFY baseline data collection was designed to inform potential data users about study procedures and baseline data collected as part of the project. The guide provides descriptions of:

  • the design of the Baby’s First Years project

  • how we came to administer a baseline interview to the n=1,050 mothers included in the publicly available dataset.

  • how the mothers were randomly assigned to high and low monthly cash gift groups

  • how we coded and otherwise processed the mothers’ responses to the instrument.

  • and show that the two groups

  • baseline characteristics and balance across the two cash gift groups

  • noteworthy features of the data that all analysts should know about


Baseline data and documentation



BFY Age 1 Data Summary

Between July 2019 and June 2020, we attempt to contact all 1,000 mothers who participate in the study and successfully interviewed 931 of them. Data collection was timed to coincide with their children’s first birthdays. Until March 13, 2020, interviews were conducted in person, often in the mother’s home. After March 13 and because of the Covid-19 pandemic, remaining interviews were conducted by telephone. Novel features of the in-home Age-1 interviews include: EEG from the child, a hair sample from the mother, and a video recorded play task with the mother and child.


The age 1 data is currently being processed and will be available in the future.


BFY qualitative study

Qualitative semi-structured interviews will be conducted with 80 randomly selected mothers in two of the four study sites.  There will be four rounds of interviews. The first round of interviews took place between August 2019 and September 2020.

Qualitative interview guides

  • Round 1 qualitative study interview guide

  • Round 2 qualitative study interview guide (not yet available)

  • Round 3 qualitative study interview guide (not yet available)

  • Round 4 qualitative study interview guide (not yet available)