The overarching theme of the dissertation is to examine the impacts of government assistance programs on the economic behaviors of disadvantaged groups such as low-income or single-headed households in the U.S. It is crucial to expand our understanding of how government assistance has helped them to overcome economic barriers to labor force participation or to expand household resources. My dissertation chapters primarily focus on the two largest government safety net programs: Temporary Assistance for Needy Families (TANF) and the Supplemental Nutrition Assistance Program (SNAP). I show that public assistance programs play a pivotal role by interacting with economic choices made by vulnerable households, such as labor supply, health, or household expenditures. Exploiting the variation in specific aspects of welfare program or the changes made to program parameters, I study how the policies have altered the life circumstances and opportunities faced by disadvantaged households.PhDEconomicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113362/1/junekim_1.pdf