This dissertation consists of three essays examining the determinants of child developmental outcomes using the Canadian National Longitudinal Survey of Children and Youth (NLSCY). The first essay estimates the relationship between birth weight and cognitive and behavioral outcomes for children aged 0 to 13. Using family fixed effects models to control for household heterogeneity, I find that every ounce counts; additional birth weight for infants born weighing less than 2,500 grams (low birth weight infants) is related to better outcomes for measures of math ability, pro-social behavior and property offense. Additional birth weight for those born weighing 2,500 grams or more is related to higher scores of motor and social development and verbal competence for young children. The second essay, using a sample of Canadian boys and girls aged 10 to 15 in dual-earner families, finds that parental work schedules play an important role in adolescents’ engagement in risky behaviour, especially for boys. Non-standard parental work schedules (i.e. work during evenings, nights, weekends and rotating shifts) are positively related to fighting, drinking and trying drugs among boys and fighting among girls. In the third essay, I investigate relationships between symptoms of hyperactivity-inattention and being read to for a sample of children aged 2 to 4. The main finding, based on family fixed effects estimates, is that children who have higher hyperactivity-inattention are read to less. However, results from interactions suggest that this relationship is only present when the person most knowledgeable of the child (usually the biological mother) has less than a post-secondary degree or diploma.