Associate Professor James Wo studies differences in crime rates among neighborhoods in towns and cities. His research shows how geography and the environment impact crime rates. Some neighborhoods in the same area have dramatically lower crime rates than others. Explaining why could help planners design cities that improve the quality of life for everyone.

James grew up in Honolulu, Hawaii, and then completed college at the University of California-Irvine. He earned his PhD there in 2017 and started as an assistant professor in the sociology department at the University of Iowa that same year. In the seven years since, Professor Wo has published a wide variety of research articles in the top journals in criminology and sociology. 

He agrees that his experiences in quite different environments from Hawaii to Southern California to Iowa City shaped his research interests, but then he quickly points out the similarities between Hawaii and Iowa.  

“Hawaii is a special place,” he says. There are many cultures, races, ethnicities. And White is not the dominant one. There’s a constant exchange among different cultures, language, music, customs. Most people consider themselves to be more than one race or ethnicity. “You end up going to people’s homes and experiencing those different customs.” 

Then there is the historical backdrop of colonialism, he says. “For Hawaiians there’s a tension between staying true to our heritage and the tourist economy. People are welcoming of other people’s interests in Hawaii. It is a tolerant culture with friendly people, and I’ve felt welcome in Iowa City, too.” People in Iowa City are as welcoming and friendly as they are in Hawaii. 

Goals for Students and Teachers

James is a popular and dedicated professor who enjoys teaching both undergraduate and graduate students. For undergraduates, he likes to strike a balance between theory and practical applications. “Hopefully, I can provide them with one skill or tidbit of a theory they can use later,” he says. Students have so many different interests but here’s something they can all use. For example, how do you figure out percent increase or decrease in crime rates? It’s the same as calculating the percentage increase or decrease in the value of a house. “It’s a skill that benefits all students,” he says. The difference going from 4 to 6 is not the same as going from 28 to 30 but people have trouble explaining why. He says that in higher education it is important to teach more than knowledge of a subject, but to also teach higher-level skills. The ability to explain the reasons for the way things are and changes that could be made will help students in their future leadership positions.

“I urge graduate students to find their passion,” he says. Then find the person in your department that does the things you want to do and does them well. “It’s OK to be assertive.” That helps students learn the skills to be successful in any job. “Go out there and introduce yourself. Find the opportunities and grab them.”

At one point, his PhD advisor told James that while he was doing many things well and was a good copilot, it was time to think about the next step. His advisor asked whether he was ready to develop a new research question and take it all the way to a published article.

“It’s about being a good student but also about being a good supervisor.” Professor Wo says. He tries to give students hints rather than telling them what to do. “This comes from the heart,” he says. “I’m not trying to be a curmudgeon!” He says that people expect professors to be ready. That’s what earning a PhD means.

Designing Crime Out of Cities

His interest in how to design cities that produce less crime goes back to the old Sim City computer game when he was growing up. Professor Wo points out that a few people in relatively small areas of a city commit most of the crimes. He gives the Ped Mall in Iowa City as an example. When the university puts out a HawkAlert, it’s often for a crime in the Ped Mall, with its shops, bars, apartments, and people hanging out near the university. What city planners call mixed-use areas present more opportunities for crime. Urban planners promote walkability in cities to make them more livable, but crime often comes with it. He also says that walkability and safety are not mutually exclusive. Finding out how to have both livability and safety is the goal of his research.

There are many things that can be done, he explains. One of them is having people talk to each other more. Develop community organizations. Technologies like cameras and lighting can help but are best used together with social networking. Nowadays there are apps like NextDoor or even Facebook that work to help people communicate with their neighbors. 

Just putting a police officer on every corner probably won’t help make a neighborhood more livable, he points out. Many people are wary of the police, especially when marginalized people are unfairly targeted. A police presence can help, though, when residents and police share information. He says that it helps when policing is fair and judicious.

Professor Wo’s latest research studies the effect of “tree canopy coverage” on crime rates in an area. Through satellite imagery and some complicated modeling, the proportion of area covered by the crowns of trees is estimated. For an article published this year in the Journal of Urban Affairs, he worked with coauthors Sarah Malone and Ethan Rogers, both of whom were trained as graduate students in our department.

The idea is that neighborhoods with more trees might make the area more livable and also reduce crime. 

Results so far suggest that trees do seem to reduce the crime rate. Areas with more trees have less crime even when a study compares neighborhoods with similar income levels. Professor Wo’s research compared the effect of tree canopy over time for the same neighborhoods. His analysis produced strong evidence that more trees resulted in less crime. There are reservations, however. More trees were associated with less violent crime and the effect was substantial. But trees had no effect on property crime. In fact, motor vehicle thefts increased with tree canopy coverage in a neighborhood. And the crime-reducing effect of tree canopy coverage is largest in the most well-off neighborhoods which already have low crime rates.

Professor Wo proposes ways in which greenspace can be restorative for a community. Greenspace could add to a neighborhood’s social capital by signaling that it has amenities and people care about each other. Also, if greenspace calms people and is mentally restorative, then potential criminals might be less apt to commit crime. So planting more trees might help make a neighborhood more livable and also safer.