Long-Run Impacts of Early Childhood Poverty: Evidence from Norwegian Registry Data Greg J. Duncan Kjetil Telle Kathleen M. Ziol-Guest Ariel Kalil

Research Questions What are the long-run impacts of low income during childhood, net of correlated family factors surrounding a child’s birth on adult achievement? Do these associations differ by the period of childhood income? How do these associations compare between Norway and the U.S.?

Background  Empirical studies suggest low-income children fare worse than higher income counterparts  Early childhood may be especially sensitive to environmental influences  Evidence of the specific role of income is limited to U.S. studies

Contributions  Add to literature on adult impacts of low income very early in life  Use longitudinal data with very high- quality measures of income throughout childhood  Compare evidence from similar birth cohorts in Norway and the U.S.

Norwegian-Specific Findings  Intergenerational earnings correlations lower in Scandinavia than in Anglo-Saxon Europe and the US (Bjorklund & Jantti, 2000)  Nevertheless, social disadvantage matters  Low income children more likely to become low-income earners (Bratberg et al. 2008)  Children of social assistance claimants more likely to claim social assistance (Lorentzen & Nilsen 2008)  Low childhood SES associated with increased mortality for most causes of death during young adulthood (Strand & Kunst, 2007)  Specific role of early income not yet established

Norwegian Data and Sample (n=765,811)  Administrative register data compiled by Statistics Norway  All children born between 1968 and 1979  Adult outcomes measured between ages 24 and as late as age 37 for the earliest cohort  Income measured prenatal to age 15; controls measured around or before birth  Adjust standard errors for presence of siblings

U.S. Data and Sample (n=1,589)  Panel Study of Income Dynamics (PSID)  Children born between 1968 and 1975  Adult outcomes measured between ages 25 and as late as age 37 for the earliest cohort  Use attrition-adjusted weights  Income measured prenatal to age 15; controls measured around or before birth  Adjust standard errors for the presence of siblings

Childhood Income  Income measured in prenatal year to age 15 (total of 17 years)  Norwegian Registry (1998 Kroner)  Taxable income originating from the tax files  Child allowance transfers  Social Assistance transfers  U.S. PSID (2005 Dollars)  Taxable income  Cash transfers

Adult Outcomes  Average annual adult earnings starting at age 24  Average weekly (Norway) or annual (U.S.) hours worked  Years of completed schooling around age 24

Sample Description Norway –49% female –42% first born –1.96 average number of siblings –Average age of mother at birth –Average education of father at birth –91% mothers married at birth U.S. –47% female –42% first born –2.21 average number of siblings –Average age of mother at birth –Average education of father at birth –84% mothers married at birth

Childhood Period Income (2005 USD) Norway  Prenatal to age 5 $38,807 (17,408)  Age 6 to age 10 $48,094 (21,094)  Age 11 to age 15 $53,824 (27,146) U.S.  Prenatal to age 5 $47,842 (28,340)  Age 6 to age 10 $54,226 (39,012)  Age 11 to age 15 $59,067 (45,369)

Adult Achievement Outcomes Norway  $32,370 average annual earnings (2005 USD)  average hours worked per week (1267 annual equivalent)  years completed schooling U.S.  $34,560 average annual earnings (2005 USD)  1892 average hours worked per year (37 weekly equivalent)  years completed schooling

Annual Earnings Standardized Regression Coefficients NorwayUS Model 1P-15.06**.31** Model 2P-15.09**.23** Model 3Ln P-15.11**.37** Model 4Ln P-5.05**.27** Ln **.06 Ln **.08

Work Hours Standardized Regression Coefficients NorwayUS Model 1P-15.05**.15** Model 2P-15.08**.11** Model 3Ln P-15.11**.20** Model 4Ln P-5.05**.20** Ln **-.03 Ln **.06

Years Completed Schooling Standardized Regression Coefficients NorwayUS Model 1P-15.18**.34** Model 2P-15.07**.14** Model 3Ln P-15.10**.22** Model 4Ln P-5.01**.10* Ln **-.04 Ln **.18**

Analysis  Average annual income in various childhood periods  Prenatal to age 5  Age 6 to age 10  Age 11 to age 15  Splines with knot at 120,000 Kroner and $25,000  Allows for distinct linear effects for average incomes up to the knot and for incomes higher than the knot

OLS Spline Model Annual Earnings (ln) NorwayU.S. P-5<120k.14**<25k.52* >120k.01**>25k.05** 6-10<120k.07**<25k.14 >120k.01**>25k <120k.12**<25k.04 >120k.01**>25k.00

OLS Spline Model Work Hours NorwayU.S. P-5<120k2.19**<25k506.74** >120k.11**>25k20.60* 6-10<120k1.06**<25k >120k.06**>25k <120k1.63**<25k74.18 >120k.18**>25k-.92

OLS Spline Model Years Completed Schooling NorwayU.S. P-5<120k.22**<25k.19 >120k.01**>25k <120k.18**<25k.65** >120k.01**>25k <120k.41**<25k-.31 >120k.05**>25k.09**

Summary  Childhood stage matters in understanding links between childhood income and adult success, although not as much in the Norwegian as in the U.S.  Larger estimated impact of increments to low income early in childhood as compared with later periods in both datasets  Steeper income gradients for U.S. than Norwegian children

Conclusions  Our results suggest evidence that the Scandinavian egalitarian welfare model helps mitigate the effects of disadvantaged family background  Nevertheless, provides supporting evidence to U.S. studies on the role of income in early childhood  Next steps: criminal charges, non-marital fertility, social assistance receipt