This project will continue the collection of data on children in the Panel Study of Income Dynamics (PSID) that is presently funded by NICHD Grant R01-HD052646. The current grant has supported the relaunch of the PSID Child Development Supplement (CDS) in 2014, allowing us to collect cross-sectional data on a new generation of children in PSID families who were all born following the launch of the original CDS cohort in 1997. Four waves of CDS have been conducted to date: three on the original cohort of children aged 0?12 years in 1997, 2002/2003, and 2007/2008, and one wave in 2014 on the next generation of PSID children born between 1997 and 2013. Our goal is to continue the transformation of CDS from a cohort design reflected in the original CDS to an on-going panel in which all children aged 0?17 years in PSID families are interviewed three times (five years apart) over the course of childhood and in which the CDS sample is refreshed each wave by adding children born since the previous wave. In addition, we will enhance CDS in 2019 by adding children from families that immigrated to the U.S. in the past 20 years, thereby ensuring that the sample is nationally representative. Data from the on-going CDS will allow studies of health, development, and well-being in childhood; the relationship between children?s characteristics and contemporaneous family decisionmaking and behavior; and the effects of childhood factors on subsequent social, demographic, economic, and health outcomes over the entire lifecourse for these individuals as they are followed into the future as part of the on-going PSID. The specific aims are to: (1) design and field a new wave of CDS in 2019, collecting data on all PSID children aged 0?17 years through interviews with primary caregivers (typically the mother) and with older children themselves (aged 8?17 years); (2) conduct assessments of reading and math skills, collect weekday and weekend time diaries, and obtain saliva samples (for subsequent genetic analysis) for all children and their primary caregivers; and (3) process, document, and distribute the new CDS data, with scale composites, time diary recodes, and individual-level links to detailed school data from the National Center for Education Statistics. The on-going CDS will provide rich, comprehensive, and up-to-date information on a large, nationally representative sample of children that includes an over-sample of African American children and a newly refreshed and representative sample of children in immigrant families. These data will be available free of charge through the PSID Online Data Center, which provides customized extracts and codebooks, detailed study documentation, and comprehensive user education and support.