The demographic transition from high birth to low birth is a fundamental process that countries undertake. It can create substantial challenges for economic growth and social policy by straining public finance. This dissertation explores the sources of low fertility and examines the effects of government policies that aim to affect fertility behavior.In the first chapter, I use a static model of fertility choices to estimate to what extent different factors contribute to low fertility in South Korea and examine the effects of child-related policies on fertility. In the model, two key factors affect fer- tility choices: the minimum consumption level required to have a child and women’s opportunity cost of raising children. The model is calibrated to match the fertility behavior of Korean women and used to examine the impact of lump-sum transfers and childcare subsidies on their fertility. I find that transfers to households per child are more cost-effective than child care subsidies. Transfers per child can reach the target fertility at a lower cost by targeting women who already have children and whose wage is sufficiently low to choose to have another child rather than work. In the case of child care subsidies, on the other hand, women who are childless or have one child and whose wage is sufficiently high to choose working over having a child are the most responsive to the policy. Thus, transfers can achieve the target fertility most cost-effectively by inducing higher-order fertility among relatively lower-wage women. In the second chapter, I document the empirical relationships between homeown- ership and fertility in South Korea. First, there is a positive relationship between the home price and fertility among homeowners. A rise in home prices by 7,346,000 KRW, equivalent to 8734.94 USD in 2010, is associated with a 2.95% increase in the mean likelihood of giving birth. Second, for renters, the same increase in the local home price in the prior year is related to a 1.24% decrease in the mean likelihood of giving birth.