The case study below that states there is a 10.5% negative impact on property values when one property in a neighborhood has graffiti.
Seo, W. & von Rabenau, B. (2011). Spatial impacts of microneighborhood physical disorder on property resale values in Columbus, Ohio.Journal of Urban Planning and Development, September 2011. Retrieved from Research Gate Click HERE
“…no other hedonic-price study has incorporated graffiti into its model, therefore the estimates here are the first to provide the impact of graffiti on property values. Specifically, one additional property with graffiti in a micro-neighborhood lowers the sale price by $11,015. This is a substantial impact and amounts to 10.5% of the average price in the sample” (Seo & von Rabenau, 2011, p. 343).