- Urban poverty: Baker has authored several books and articles about urban poverty, in particular in New York City. His work has focused on the ways in which poverty affects individuals, families, and communities, as well as the policies that can be implemented to address it.
- Race and inequality: Baker has written extensively about the intersection of race and inequality in the United States. He has argued that racism is a systemic issue that affects all aspects of society, from education and housing to employment and criminal justice.
- Social policy: Baker has written about various social policies, including welfare, housing, education, and health care. He has argued for policies that promote social justice and equity.
- Urban planning: Baker has written about urban planning and development, particularly in New York City. He has argued for planning that promotes sustainable development, affordable housing, and community engagement.