Krzysztof Karbownik

For Some Mothers More than Others: How Children Matter for Labour Market Outcomes When Both Fertility and Female Employment are Low

We estimate the causal relationship between family size and labour market outcomes for families in low fertility and low female employment regime. Family size is instrumented using twinning and gender composition of the first two children. Among families with at least one child we identify the average causal effect of an additional child on mother’s employment to be -7.1 percentage points. However, we find no effect of additional children on female employment among families with two or more kids. Heterogeneity analysis suggests no causal effects of fertility on female employment among mothers with less than college education and older mothers (born before 1978). Furthermore, we find evidence for the interaction of family size with maternal education and age. An unintuitive feature of our finding is that we identify a positive bias of OLS estimates for highly educated mothers and for mothers born after 1977.

Education Research and Administrative Data

Thanks to extraordinary and exponential improvements in data storage and computing capacities, it is now possible to collect, manage, and analyze data in magnitudes and in manners that would have been inconceivable just a short time ago. As the world has developed this remarkable capacity to store and analyze data, so have the worlds governments developed large-scale, comprehensive data files on tax programs, workforce information, benefit programs, health, and education. While these data are collected for purely administrative purposes, they represent remarkable new opportunities for expanding our knowledge. This chapter describes some of the benefits and challenges associated with the use of administrative data in education research. We also offer specific case studies of data that have been developed in both the Nordic countries and the United States, and offer an (incomplete) inventory of data sets used by social scientists to study education questions on every inhabited continent on earth.

Socioeconomic status and genetic influences on cognitive development

Significance A prominent hypothesis in the study of intelligence is that genetic influences on cognitive abilities are larger for children raised in more advantaged environments. Evidence to date has been mixed, with some indication that the hypothesized pattern may hold in the United States but not elsewhere. We conducted the largest study to date using matched birth and school administrative records from the socioeconomically diverse state of Florida, and we did not find evidence for the hypothesis. Accurate understanding of environmental moderation of genetic influences is vital to advancing the science of cognitive development as well as for designing interventions. One widely reported idea is increasing genetic influence on cognition for children raised in higher socioeconomic status (SES) families, including recent proposals that the pattern is a particularly US phenomenon. We used matched birth and school records from Florida siblings and twins born in 1994–2002 to provide the largest, most population-diverse consideration of this hypothesis to date. We found no evidence of SES moderation of genetic influence on test scores, suggesting that articulating gene-environment interactions for cognition is more complex and elusive than previously supposed.

Educational Performance of Children Born Prematurely

Importance Survivors of preterm birth often present with medical morbidities; however, variation in their long-term educational performance has not been well described. Objective To estimate the association between gestational age and 4 outcomes in school-aged children: readiness to enter kindergarten, scores on standardized tests in elementary and middle school, gifted status, and low performance. Design, Setting, and Participants In a retrospective cohort study, children born in Florida between 1992 and 2002 at 23 to 41 weeks’ gestation who entered Florida’s public schools between 1995 and 2012 were assessed for kindergarten readiness and tested in mathematics and reading in grades 3 through 8. Data analysis was performed from January 12, 2016, to March 1, 2017. Exposures Gestational age at birth. Main Outcomes and Measures Kindergarten readiness, scores on the Florida Comprehensive Achievement Test (FCAT), classified as gifted, and classified as low performance. Results A total of 1 527 113 singleton infants with gestational ages of 23 to 41 weeks born between 1992 and 2002 were matched to Florida public school records. Of these, 1 301 497 children were included in the analysis; 641 479 (49.3%) were girls. A total of 301 (65.0%) Florida children born at 23 to 24 weeks’ gestation were designated as ready to start kindergarten. When the FCAT test scores were adjusted for potentially confounding maternal and infant variables, children born at 23 to 24 weeks’ gestation performed 0.66 SD (95% CI, −0.73 to −0.59) lower compared with those born at full term. A total of 123 554 (9.5%) of all Florida-born public school students were considered gifted, including 17 (1.8%) of those born at 23 to 24 weeks’ gestation. In comparison, 75 458 (5.8%) of all Florida-born public school students were low performing; 310 (33.5%) of these children had been born at 23 to 24 weeks’ gestation. Kindergarten readiness, FCAT scores, and gifted status were positively related to gestational age, whereas low performance was inversely related to gestational age. Conclusions and Relevance Although gestational age has long been associated with poor educational performance, a sufficient proportion of children born near the limits of viability performed within expected school norms, warranting further investigation into how and why certain children are able to overcome the educational burdens that may follow preterm birth.

For Some Mothers More than Others

We estimate the effect of family size on female labour supply using data from Poland and instrumenting for family size with twinning at first and second birth. To the best of our knowledge, this is the first study to causally address this relationship in a post‐communist country. We identify the average causal effect of an additional child on mothers employment to be −7.0 pp, but we do not find significant effects of additional children on female employment among families with two or more children. Furthermore, we identify a positive bias of OLS in the estimates among highly educated mothers and those from younger cohorts.