Krassa studies the impact of the built and natural environment in which people reside upon on their attitudes, beliefs, and behaviors. His research examines how the built environment helps shape people’s activity levels as well as their propensity to make friends (or not) with their neighbors. His work also looks at whether green spaces mitigate or exacerbate problems presented by food deserts and crime by shaping local social networks. He is particularly interested how the built and natural environment affects neighborhood social relations, commitment to place, resident health, NIMBYism, and participation in local affairs. Krassa’s research also focuses on the social effects of public and economic policies, in particular the impacts each has upon those directly affected as well as the consequences on the national population as a whole.