Tag Archives: philadelphia

eyes on the street

A group at the University of Pennsylvania looked for statistical evidence that “eyes on the street” are a deterrent to crime. The results are a bit puzzling, as real world data often can be.


Statistical analyses of urban environments have been recently improved through publicly available high resolution data and mapping technologies that have adopted across industries. These technologies allow us to create metrics to empirically investigate urban design principles of the past half-century. Philadelphia is an interesting case study for this work, with its rapid urban development and population increase in the last decade. We focus on features of what urban planners call vibrancy: measures of positive, healthy activity or energy in an area. Historically, vibrancy has been very challenging to measure empirically. We explore the association between safety (violent and non-violent crime) and features of local neighborhood vibrancy such as population, economic measures and land use zoning. Despite rhetoric about the negative effects of population density in the 1960s and 70s, we find very little association between crime and population density. Measures based on land use zoning are not an adequate description of local vibrancy and so we construct a database and set of measures of business activity in each neighborhood. We employ several matching analyses within census block groups to explore the relationship between neighborhood vibrancy and safety at a higher resolution. We fi nd that neighborhoods with more vacancy have higher crime but within neighborhoods, crimes tend not to be located near vacant properties. We also find that more crimes occur near business locations but businesses that are active (open) for longer periods are associated with fewer crimes.

This is particularly fascinating to me because I live my life in the middle of this particular data set and am part of it. So it is very interesting to compare what the data seem to be saying with my own experiences and impressions.

The lack of correlation between population density and crime is not surprising. Two neighborhoods with identical density can be drastically different. The correlation between poverty and crime is not surprising – people who are not succeeding in the formal economy and who are not mobile turn to the informal economy, in other words drug dealing, loan sharking and other illegal ways of trying to earn an income. If they are successful at earning an income, they tend to have a lot of cash around, and other people who know about the cash will take advantage of them, knowing they will not go to the police. Other than going to the police, the remaining options are to be taken advantage of repeatedly, or to retaliate. This is how violence escalates, I believe, and it goes hand in hand with development of a culture that tolerates and even celebrates violence, in a never-ending feedback loop.

The puzzling part comes when they try to drill down and look at explanatory factors at a very fine spatial scale. They found a correlation between crime and mixed use zoning, which appears to contradict the idea that eyes on the street around the clock will help to deter crime. And they found more crime around businesses like cafes, restaurants, bars and retail shops. They found that longer open hours seemed to have some deterrent effect on crime relative to shorter open hours.

I think they have made an excellent effort to do this, and I am not sure it can be done a lot better, but I will point out one idea I have. They talk about some limitations and nuances of their data, but one they do not mention is the idea that they are looking at reported crimes, most likely police reports or 911 calls. It could be that business owners, staff and patrons are much more likely to call 911 and report a crime than are residential neighbors. The business staff and patrons may see this as being in the economic interest, increasing the safety of their families, and the (alleged) criminals they are reporting are generally strangers. In quieter all-residential neighborhoods, people may not observe as many of the crimes that do occur (fewer “eyes on the street”), they may prefer not to report crimes either through a sense of loyalty to one’s neighbors, minding one’s own business, quid pro quo, or in some cases a fear of retaliation. There is also the factor of some demographic groups trusting the police more than others, although the authors’ statistical attempts to control for demographics may tend to factor this out.


why I don’t bike in Philadelphia

I’m a huge believer that bicycling should be the second most common form of transportation in cities, after walking. Walking is the perfect way to run errands in a residential neighborhood. Some people are lucky enough to be able to walk to work, but not everybody wants to live in the central business district, so the nicest neighborhoods are often a few miles from the center, a little far to walk but perfect for biking. Biking promotes the perfect city layout, and the perfect city layout promotes biking. It also saves time, promotes exercise, physical and mental health, saves energy, promotes cleans air, and is good for business. So I’m a huge believer. But I don’t bike very much. Occasionally on the weekend for recreation, but almost never on weekdays to get to work, and absolutely never to take children to and from school. Here’s why:

On a bicycle in Philly, I’ve been spit on, cussed at, honked at, clipped by rearview mirrors, and told to do things to myself that can’t be written in any respectable publication. More times than I can count, I’ve had vehicles clearly try to make a point by speeding by me way too closely … only to be stopped at a red light half a block away. And all for riding my bike in a legal, responsible way…

But what about all those scofflaw bikers, blowing through stop signs and weaving through traffic with their devil-may-care attitudes? Bikers just don’t follow the rules of the road! …

But, I’ve also got some top-secret info: Cars in Philly break traffic laws, too. In fact, you might think that sliding through a stop sign perfectly, pulling a fast U-turn on Broad Street, driving down a one-way street the wrong way, and texting while driving, steering with your knees, are all on the PennDOT driving test. (Swerving around potholes and deciphering parking signs is probably on there too.) Because we’ve all seen cars do these things, and more, in Philly. All the time.

And the fact is, when drivers do these things surrounded by two tons of steel, it’s a whole lot more dangerous for everyone on the street and sidewalks than when a bicyclist does the same with a 20-pound bike.

Recently, City Council President Darrell Clarke said, “This is Philadelphia. People drive to the corner store. This is what we do.”


“This is what we do,” sounds a whole lot like “This is the way we’ve always done things.” And “this is the way we’ve always done things” has got to be the laziest, worst excuse for doing anything ever…

Those are appalling statistics. Philly’s got a problem. And it has to do with cars hitting bicyclists.

What’s best for the city is not the status quo. What’s best is more protected bike lanes, real progress toward Mayor Kenney’s commitment to Vision Zero, and more access to modes of transportation other than private vehicles.

I couldn’t agree more. One thing the article doesn’t mention is that the police openly state that they don’t enforce the traffic laws because they are busy fighting violent crime on our city’s streets. Well, how exactly is the murder of pedestrians and bicyclists on our city’s streets by illegal driver behavior not considered violent crime on our streets?

Enforcement could help in the short term, but human behavior should be taken mostly out of the equation by better street design in the longer term. Safe street designs have been nearly perfected in Northern Europe and are slowly coming to U.S. cities, even including our cousins over in Pittsburgh. But in Philadelphia, supposedly a leader on progressive policies, our political and bureaucratic leaders seem to believe that what is common in sister cities is crazy or impossible here, because they have apparently never left the county. People are dying as a result of these ignorant cowards.

I would love to see Mr. Kenney show real leadership and appoint some real leaders instead of the same old ignorant, cynical, can’t-do bullshit that has held Philadelphia back from being a world-class city for decades. It seemed like we were finally turning the corner under Mayor Nutter, but it seems to me that we are backsliding now. Please prove me wrong, Mr. Kenney!

Donald Shoup

I can never get enough Donald Shoup. Here are some policies he suggested at a recent talk in Philadelphia:

  • parking benefit districts, where parking revenues go to street and pedestrian improvements, so people can see what they are paying for
  • parking permit blacklists – essentially, people who move into new buildings without parking are not allowed to apply for city parking permits. This might seem unfair, but in my neighborhood in Philadelphia one way existing residents are able to hold up new development is by raising parking concerns with their elected politician. So this could be politically practical in that it might remove one of the sticking points between long-established residents and newcomers. At least, alleviating this one concern might allow people to move on and tackle others. It would force the new developments to either provide onsite parking, or just develop in places and ways where people are not going to demand as much parking. You could drop any minimum parking requirements and let the market decide.
  • Parking cash-out – employees who choose not to use company-paid parking can opt for a cash payment instead. California has done this apparently and it makes sense to me. It removes a perverse incentive for some people to choose driving to work over other options.
  • build transit passes into University fees

Philadelphia prison population might be cut by a third

I found this news pretty surprising:

Philadelphia’s prisons hold on average more than 7,000 inmates each day – the highest incarceration rate of any major American city.

The powers that be want to cut it by more than a third, 34 percent to be exact, during the next three years.

Part of that will call for addressing racial bias in the justice system… “Folks cannot get what they need in the way of drug treatment, counseling, job training, social skill training behind bars,” said Mayor Jim Kenney.

The article goes on to quote judges who agree with this. It’s certainly good news. If so many people involved in the system agree that one-third of people in prison are there because of racial bias, are nonviolent, and don’t need to be there, and it can really be fixed so quickly, what took so long?


more on Alice Goffman

Recently I was talking about how much I enjoyed On The Run: Fugitive Life in an American City. I knew there was some controversy over the book, but I didn’t realize how much. I actually assumed she was a journalist, but it turns out she is a sociologist and some sociologists think they are not supposed to write books like that. (Later though, the article says that journalists have criticized her and sociologists have defended her, so I am a little confused there.) I don’t think I know any sociologists, or a lot about them. Once I knew an anthropologist, and I asked him how he was different from a sociologist, but he just laughed and never answered my question. The problem, some say, is that she got too close to her subjects, was too quick to repeat everything they told her, and reinforced stereotypes. On the last, I think that is completely false. If anything, she does a lot to humanize and find redeeming qualities in people who do some risky and violent things. As for the way she got personally involved with her subjects, that is what makes the story so engaging. I think ultimately it is a story told from a certain point of view, and you have to keep that point of view in mind almost as though you were reading a novel. Whether that is good academic sociology or not I wouldn’t know, but I enjoyed the book.

By the way, Alice Goffman did a TED talk which is more or less a summary of the book.

Philadelphia rowhouses

I didn’t realize just how unusual the Philadelphia rowhouse is. Baltimore is really the only city that has something similar on a similar scale, with D.C. a distant third. I didn’t grow up here and was skeptical at first, but now I am living in my third one and I am completely sold. They are high density, yet low rise and to me, don’t feel as cramped as high rise apartments would. They are pretty social – people sit on their front stoops and get to know their neighbors, especially in good weather. They have back yards big enough to enjoy but small enough to be low maintenance. They are not conducive to driving and parking (a source of frustration to many), and are extremely walkable as a result. People walk to their jobs and shopping. Kids walk to school. There isn’t a whole lot of open space, I admit, but a few good parks and trails within easy walking distance make up for that.


enjoying the festive papal atmosphere

Here is some helpful advice from the state of Pennsylvania (our friends in rural Pennsylvania, I’m thinking) on how to enjoy yourself at the papal visit.

If you get caught up in a crowd of people:

  • Try to walk around crowds, rather than through them.
  • Stay on your feet – do not sit down or bend down to pick up something.
  • If you fall down, get back up on your feet as quickly as possible.
  • Move with the flow of people, rather than against the flow.
  • Carefully and safely make your way toward the edge of the crowd.

It bears repeating – when in the big city, be aware of your surroundings at all times, tuck your wallet into one of your socks, and do not…repeat…do not under any circumstances bend over.

Brad Pitt at the World Meeting of Families

Today was a pretty tranquil scene in Philadelphia. Although parts of the city resembled a sort of soft military occupation – police, uniformed soldiers (who were polite and helpful), TSA and border patrol (who weren’t), it was actually quiet in the absence of traffic and with a lot of people staying home from work. In the morning, people seemed to confine themselves to sidewalks out of habit, then gradually during the day, they fanned out into the streets.
IMG_0296 (2)

Contrast this with what is expected tomorrow…

Okay, so that’s the Philadelphia scene from World War Z… which was actually filmed in Scotland with some Philadelphia landmarks photo-shopped in.


I engaged in some Comcast bashing recently. I’m not really sorry. You can argue that they do a lot for the Philadelphia economy. Well, that would also be true if they were manufacturing land mines. But here’s an article talking about how they do support some local startup companies.

Comcast invests in local startups through Genacast Ventures, a partnership between investor Gil Beyda and Comcast Ventures that helps fuel early-stage companies in the area, including LeadID, Invite Media and Packlate.com. One past success is a seed investment in Divide, a bring-your-own-device enterprise security company formerly known as Enterpriod. Divide eventually sold to Google.

“Our passion has always been to turn great ideas into powerful businesses — and that starts with finding talented entrepreneurs,” said Beyda, who leads Genacast Ventures. “Comcast Ventures, with the help of the Genacast and Catalyst funds, has provided unparalleled strategic and financial support for entrepreneurs just getting started. Identifying innovative leaders is the mission of all our partners, and the ability to support them with the assets from Comcast and NBCUniversal provides startups with a distinct advantage.”

Comcast has also collaborated with DreamIt Ventures to invest in minority-owned startups, including Philly outfits ROAR and LIA Diagnostics.