In the first chapter titled "Cognitive Ability, Education, and Fertility Risk", I explore the role of cognitive ability in fertility timing. Women in the bottom quartile of the cognitive ability distribution are nine times more likely to have their first child as a teenager. First, I document the differences in age at childbirth by cognitive abilities and the fact that this relationship persists after controlling for wage, education, demographics, and measurement errors. Subsequently, utilizing NLSY79 data, I build and estimate a life cycle model to jointly study the relationship between contraception efficiency, age at childbirth, education, wages, and marriage. Then, I answer through the model's lens whether low educational outcomes among teenage mothers are due to the cost of attending college with a child or if they have children earlier because they do not attend college. I find that college is too costly for teen mothers, even without a child, so postponing maternity does not lead to higher college attendance. Finally, I explore the 32% reduction in teen pregnancies during the 1990s and 2000s. According to the model, the decline in teen pregnancies was primarily driven by an increase in women's wages, contraception efficiency, and a reduction in the cost of attending college. In the second chapter "The Role of Parental Altruism in Parents' Consumption, College Financial Support, and Outcomes in Higher Education", I analyze how parent-child interactions and parents' altruism impact college financial support and outcomes. Firstly, I document how wealthy parents with poor children change their consumption patterns. Finding that a poor child reduces parent consumption by 2000 dollars annually. Then I use a dynamic altruistic overlapping generations model, in which parents and children interact each period to study if parents use college financial aid as a mechanism to reduce future overconsumption, helping to explain the highest graduation rates for low-ability children with wealthy parents, compared to low-ability children with non-wealthy parents. The model explains 60% of the college graduation gap among low-ability students of different parental wealth. Finally, in the third chapter, "Fiscal and Generational Imbalances in the U.S. Federal Budget", joint with Jagadeesh Gokhale and Kent A. Smetters, we use the Penn Wharton Budget Model's microsimulation and U.S. demographic projections to estimate federal fiscal and generational imbalances. First, we utilized survey data to estimate the average per-capita payments of each type of government tax and transfer by education, age, race, and cohort. Next, we used the Congressional Budget Office's (CBO) aggregate payment projections to estimate per capita government taxes and benefits for each group until 2030. As the CBO only submits forecasts until 2030, we assumed that tax and transfer growth would continue at the labor productivity rate thereafter. Finally, we aggregated all taxes and transfers, accounting for population growth and demographic changes. Based on our analysis, the federal government's fiscal imbalance (FI) under current fiscal laws and purchase policies over the next 75 years is 7.0 percent of the present value of projected GDP (PVGDP), and calculated in perpetuity, it is 8.2 percent of PVGDP. Furthermore, the FI as a share of the present value of federal expenditures over the next 75 years equals 29.8 percent, while it equals 38.6 percent as a share of the present value of federal revenues implying that to keep the fiscal balance, the government should reduce expenditures or increase taxes in the previous magnitudes. We also measure the generational imbalance (GI) for Social Security and Medicare Part A, which shows the present value of net benefits in excess of taxes paid by past and currently alive generations. Our findings indicate that the imbalance for past and current generations amount to $44.7 trillion, while the imbalance for future-born generations is $38.4 trillion. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]