The past year has been busy for Philly — and for researchers who study city policy. As the year ends, we’ve rounded up a few recent studies on Philadelphia to help inform our conversations in 2020.

Gentrification and community

The causes of gentrification and its impact on displacement get a lot of attention — not so much on what it means to live in a gentrified community. A study published in Urban Studies earlier this year looked at the effect of gentrifiers’ race on residents’ feeling of belonging. The researchers found that residents of gentrifying neighborhoods had a lower sense of community than nongentrifying neighborhoods — depending on gentrifiers’ race. For neighborhoods where black and Hispanic residents moved in and white residents moved out, gentrification improved the sense of community. When white people moved in — even without displacement — residents’ felt less of a connection.

Why does this matter to Philadelphia? Feelings of social isolation and not belonging drive gun violence, drug use, poor health, and reduced well-being. The research suggests that gentrification policy must go beyond preventing displacement to also tackle social isolation.

Soda tax

The Philadelphia sweetened beverage tax is the type of novel policy that public health researchers live to evaluate — and in 2019, it was evaluated a lot. The impact has generally been positive but not dramatic. The two most positive results come from studies coauthored by researchers in the city’s Department of Public Health. The first found that Philadelphians bought 38% fewer sweetened beverages after the tax’s implementation — even after accounting for increased purchases in nearby counties.

The second found that the soda tax did not lead to layoffs in supermarkets, grocery stores, and soft drink manufacturers in Philadelphia compared with nearby counties.

But other researchers found a less rosy picture. Health economists asked children and adults about their soda consumption at the exits of grocery stores a year before and after the tax. They found that the tax decreased adults’ consumption by about a small soda a day but had no impact on most children. Further, two researchers from St. Joseph’s University found that the soda tax did not lead consumers to shift their habits to healthier options.

Why does this matter to Philadelphia? The soda tax was imposed to raise revenue, not primarily to shift health outcomes. But these studies offer information and evaluation to inform discussion. That is dramatically different than most policy discussions in Philadelphia — where assumptions, and not data, rules.

Police body-worn cameras

Between May 2016 and April 2017, the Philadelphia Police Department ran a one-year pilot with body-worn cameras — which record police officers’ interactions from their perspective — in a North Philadelphia police district. In November, Temple University criminal justice researchers published their results from evaluating the pilot. They found that compared with three nearby police districts, police officers who were assigned body cameras were much less likely to use force with, stop, or arrest pedestrians. The number of vehicle stops and citizen complaints, however, did not change.

Why does this matter to Philadelphia? We are spending millions of dollars to outfit every officer with a body camera. The research suggests it might be a worthwhile investment — if it’s used correctly, including making sure they are actually turned on.

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Environmental injustice in green infrastructure

As the city feels the impact of climate change more and more, it is critical that we update our infrastructure to be more resilient and energy-efficient. But a new study conducted by researchers from Barcelona, Spain, and published in the journal Urban Climate shows that efforts to make infrastructure green can entrench injustice.

Philadelphia is considered a leader nationwide for green infrastructure improvements to stormwater management — such as rain gardens, green roofs, and tree trenches that help reduce wastewater runoff and prevent flooding. In the past two decades, the city made close to 12,000 improvements — but spread unequally across the city. The researchers found that, generally, the least vulnerable populations received the most improvements. Areas that enjoyed green resilience infrastructure are also some of the most gentrified neighborhoods. The authors concluded that green improvements are both a driver and a consequence of gentrification — gentrifiers are drawn to them and demand them.

Why does this matter to Philadelphia? Our city is already segregated by unequal development. That spells unequal climate impact. On hot summer days, different neighborhoods can experience a temperature difference as big as 20 degrees. It is critical that as the city moves forward to mitigate climate change, we amend past injustices and not entrench them.

Brain Trust is a biweekly column that looks at how new research affects Philly. Ideas? Suggestions? Email agutman@inquirer.com.