Where 'Nextdoor' communities exist and what these communities talk about

"Nextdoor" is the world's largest hyperlocal social media network, used by 13% of American adults. Yet little is known about the make-up of the actual neighborhoods—numbering approximately 220,000 across the United States—in which these accounts exist and what people in those communities talk about on the platform.

To address our limited understanding of this population, a team of New York University and University of Michigan researchers generated a demographic portrait of communities in which Nextdoor neighborhoods exist, the presence of public agencies in those communities, and what topics are most often discussed.

Using U.S. Census data, other publicly available information, and posts from a sample of Nextdoor neighborhoods, the study showed the following:

• Nextdoor neighborhoods are more likely to be located in communities that are less dense, Whiter, wealthier, older, and more educated.
• Government agencies, and law enforcement agencies in particular, are more likely to be present on Nextdoor in communities that have a higher proportion of non-White residents, greater levels of income inequality, a higher average home value, and higher incomes.
• In terms of topics discussed by users, posts seeking and offering services are by far the most popular—but posts reporting potentially suspicious people or activities received the highest engagement.

"Research on social media tends to focus on national and international political discussions happening on large platforms, such as Facebook, X, and YouTube," says Zeve Sanderson, founding executive director of NYU's Center for Social Media and Politics (CSMaP) and the co-lead author of the paper, which appears in the Journal of Quantitative Description: Digital Media.

"But this limits our understanding of the digital media ecosystem as a whole, and its relationship with local communities and civic life in particular.

"These findings contribute to our understanding of a widely used localized platform—Nextdoor users cover an estimated nearly one-third of U.S. households—by showing what the real-life neighborhoods of Nextdoor's 'digital town squares' look like."

One unique feature of Nextdoor is that public agencies, such as local government, law enforcement, and school districts, can join the platform through the Nextdoor for Public Agencies program. However, the presence of law enforcement agencies, paired with posts categorized as "crime and safety," has drawn criticism for contributing to community policing and surveillance, often with racialized impacts. The researchers looked at the presence of public agencies, as well as the topics of user posts, to better understand these dynamics.

"We don't know why law enforcement agencies are more likely to be present in Nextdoor neighborhoods with more non-white residents," observes CSMaP Graduate Research Affiliate Megan A. Brown, co-lead author of the paper and a current Ph.D. student at the University of Michigan.

"They could be there to better engage with the community, to facilitate surveillance by community members, or some combination of the two. Analyzing the behavior of law enforcement agencies on Nextdoor is a promising line of future research."

In addition to illuminating the makeup of these neighborhoods, the researchers studied what these communities discussed. Using a sample of 30 Nextdoor neighborhoods, Sanderson, Brown, and their colleagues collected daily online posts and comments on the pages' main feed—nearly 116,000 posts and approximately 164,000 comments—and other data (although direct messages and those on Nextdoor private groups were not collected). Here they found the following:

• Posts seeking or offering services were the most frequent, followed by neighborhood logistics—such as lost pets, transportation issues, and events—and pleasantries, such as holiday wishes and celebrating local weather.
• Discussion of perceived suspicious persons, which some reporting has suggested enables racialized community surveillance on Nextdoor, was infrequent relative to the other more popular categories, but still accounted for roughly 6% of the collected posts.
• However, posts reporting perceived suspicious people or activities received the highest average number of comments, showing that engagement on a topic differs from posting frequency.

"Information sharing is an important indicator of social capital formation, and the neighborhoods analyzed in this study provide evidence this is occurring," Sanderson concludes. "However, while Nextdoor has made changes designed to combat racial profiling and surveillance on the platform, discussions on suspicious persons could still prompt biased behavior by law enforcement."

The paper's other authors included Sarah Graham, CSMaP's research operations manager, Minjoo Kim, an NYU undergraduate research assistant, Solomon Messing, a research associate professor at NYU and CSMaP, and Joshua A. Tucker, professor of politics at NYU and co-director of CSMaP.

Data and users' posts were collected after obtaining consent of the individuals living at those addresses and, to preserve privacy, personally identifiable information was separated from the analysis.