Tag Archives: social networks

Analysis of the non-fatal gunshot social network in Chicago

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Sociologist Andrew Papachristos has a recent paper looking at the social networks involved in non-fatal gunshots in Chicago:

Papachristos constructs a social network—not a virtual one in the Facebook sense, but a real one of social connections between people—by looking at arrestees who have been arrested together. That turns out to be a lot of people in raw numbers, almost 170,000 people with a “co-offending tie” to one another, with an average age of 25.7 years, 78.6 percent male and 69.5 percent black. It’s also a large percentage of all the individuals arrested: 40 percent of all the individuals arrested during that period.Within the entire group, the largest component of that whole co-offender group has 107,740 people.

Within the timeframe—from 2006 to 2010—70 percent of all shootings in Chicago, or about 7,500 out of over 10,000, are contained within all the co-offending networks. And 89 percent of those shootings are within the largest component.

Or, to put another way: the rate of gunshot victimization (nonfatal + fatal) in Chicago is 62.1 per 100k. Within a co-offending network, it’s 740.5—more than 10 times higher.

This sounds very similar to his research on murders: being part of a particular social network dramatically increases the risk of being part of a shooting. One implication is gun crime in Chicago isn’t simply about being in a disadvantaged neighborhood or in the wrong place at the wrong time; it is about how you are tied to other people.

The article goes on to an interesting interview where Papachristos talks about data issues (collecting the right data, being able to put it into network form) and translating findings such as these into policy choices.

Get better ideas by interacting with others with different ideas

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One secret to innovation is to interact with people who differ from you and are outside your closer network:

The tendency of people to seek out insights from people in different fields, different organizations or of different mindsets is called “brokerage” and has been carefully studied by academics.

It can lead to better ideas, better promotions, and better salaries — whether you work in product design, contracting or finance…

But if you’re charged with innovation, you need to branch out and build brokerage, said Ronald Burt, the Hobart W. Williams Professor of Sociology and Strategy at the University of Chicago Booth School of Business.

“It’s essential,” Burt said. “The new ideas we come up with come from the places where we vary. A person who only knows about the variation in what they do will get better at what they’re doing, but will always come to the same place.”

Burt goes on to discuss how people need two sets of connections: close ones (which helps provide closure) and a few regular connections with distant people (weak ties) who will provide you with different perspectives outside your close group. This all emphasizes the power of social networks: information (as well as other things like motions) can be passed through a network through the social connections.

Social network analysis of Chicago violence show differences in risk, differences compared to Boston

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Read a summary of recent research by sociologist Andrew Papachristos about social networks and violence in Chicago:

Take, for instance, a 2013 paper, published with Yale colleague Christopher Wilderman in the American Journal of Public Health. It’s set in a community in Chicago with a litany of familar risk factors: half of all households were led by a single female; 43 percent of the 82,000 residents had less than a high-school education; a third of households were below the poverty line. And the homicide rate, over the five years of the study, was 55.2 per 100,000, about four times the citywide rate (Daniel Hertz’s maps of homicide rates by police district are a good way of putting that in context; it’s high.)…

Simply being arrested during this period increases the aggregate homicide rate by nearly 50%, but being in a network component with a homicide victim increases the homicide rate by a staggering 900% (from 55.2 to 554.1)…

Even in this extremely abstracted form, from a third paper by Papachristos you can see a remarkable contrast between gang violence in Chicago and Boston. Each node is a gang; each line is a homicide or shooting; each bidirectional line is a reciprocal homicide…

Chicago’s social network of homicide is a knotty mess: 98 percent of all Chicago gangs were connected within the city’s homicide network during that timeframe, 32 percent higher than Boston’s shooting network. The network density of black gangs in Chicago is particularly intense, 30 percent compared to 4.5 percent for Latino gangs…

And a place to start for gathering more data—as Papachristos points out, his analysis is limited to people doing bad things. Robert Sampson, the Harvard (by way of Chicago) sociologist, has done pioneering work, most recently in his book Great American City, showing how positive social networks reduce crime and improve public-health outcomes in socially-organized neighborhoods like Chatham. Another possible implication is figuring out what kinds of networks “inoculate” people from violence.

Looks like a good summary of some interesting research. On one hand, this should be reassuring to the public: the perception is that crime rates in Chicago are out of control (even as they have declined in Chicago over the years and in many American cities) yet much of the violent crime is in the hands of a relatively small group of people. On the other hand, the density of violence in Chicago suggests there are some serious issues in particular social interactions and locations that are not easy to solve.

I’m also reminded of the work of sociologist Sudhir Venkatesh who has argued in several books that gangs in Chicago as well as more informal black market networks might be considered “efficient” or “rational” in what they do because of a lack of legitimate opportunities in poor neighborhoods. Whereas legal businesses might seek the best way to make profits, social networks in disadvantaged neighborhoods make do with what they have, even if the means are not legitimate. This doesn’t condone violence or other illegal behavior but Venkatesh’s work shows these aren’t haphazard or chaotic social networks and interactions.

Sociologist/CIA fellow describes “the paradox of the war on terror”

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A recent sociology dissertation asked members of the CIA to describe their work and the “war on terror”:

Nolan, a CIA Graduate Fellow in sociology, produced the ethnography by making observations and interviewing 20 analysts in NCTC’s Directorate of Intelligence (DI) while also working full time as a counterterrorism analyst at Nation Counterterrorism Center (NCTC) from January 2010 to January 2011.

She notes that many analysts feel overwhelmed because “they often were not really sure what their jobs were, and they felt that they had very little understanding of what other people in the organization do.”…

What Anna detailed is the paradox of the War on Terror: The U.S. is fighting, but there are no clear day-to-day objectives. There is an enemy, but it is more of a network than an entity. There is an objective, but there is no clear way to win.

Last year The Washington Post, in a report on the NTCT’s disposition matrix, noted that Obama administration officials believe that U.S. global kill/capture operations “are likely to be extended at least another decade. Given the way al-Qaeda continues to metastasize, some officials said no clear end is in sight.”

I’m not quite sure this is confusing, as the article then goes on to suggest. This is a new kind of operation but the parameters are not entirely unknown. The U.S. is working against social networks, which take time to understand and track. (Think of recent efforts for academics and police to analyze the social networks of gangs.)

However, we could ask whether this new reality matches the kind of bureaucratic structure common in larger organizations. If the objectives change consistently as does the information coming in, it seems like there has to be a corresponding structure that allows smaller units to act somewhat independently and quickly respond to situations. Yet, more smaller and independent units still require coordination so they are not working at cross-odds or important information and actions fall through the cracks.

Similarly, it requires a different mentality from the public who might prefer clearly defined operations. Fighting terrorism is not that. Even when there are “successes,” it can take years to lead to them. “Winning” is not one-time event where a peace treaty is signed but rather the ongoing amount of time citizens in the United States are not threatened. (Americans have some experience with these ongoing wars. See the war on drugs and the war on poverty.)

It seems like there is a lot of room here for sociologists to investigate the war on terrorism, the military, the government, and the responses of the American public. Sociologists may have shied away from military sociology in recent decades but this is a critical component for understanding today’s world…

“The Strength of Weak Ties” means Twitter relationships are more helpful than those on Facebook

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Clive Thompson applies sociologist Mark Granovetter’s famous findings regarding weak ties to a comparison of relationships on Twitter and Facebook:

In 1973, sociologist Mark Granovetter gave a name to this powerful process: “The Strength of Weak Ties.” Granovetter had spent time researching the ways in which people found new jobs. After surveying hundreds of job finders, he discovered there were three main strategies: responding to job advertisements; direct application and coldcalling; or harnessing personal contacts…

But the second finding was even more intriguing: When people got these word-of-mouth jobs, they most often came via a weak tie. Almost 28 percent of the people heard of their job from someone they saw once a year or less. Another 55.6 percent heard of their job from someone they saw “more than once a year but less than twice a week.” Only a minority were told of the job by a “strong tie,” someone whom they saw at least twice a week. To put it another way, you’re far less likely to hear about a great job opening from a close friend. You’re much more likely to learn about it from a distant colleague…

For example, Facebook’s news feed analyzes which contacts you most pay attention to and highlights their updates in your “top stories” feed, so you’re liable to hear more and more often from the same small set of people. (Worse, as I’ve discovered, it seems to drop from view the people whom you almost never check in on — which means your weakest ties gradually vanish from sight.) As Pariser suggests, we can fight homophily with self-awareness—noticing our own built-in biases, cultivating contacts that broaden our world, and using tools that are less abstruse and covert than Facebook’s hidden algorithms.

If you escape homophily, there’s another danger to ambient awareness: It can become simply too interesting and engaging. A feed full of people broadcasting clever thoughts and intriguing things to read is, like those seventeenth-century coffee shops, a scene so alluring it’s impossible to tear yourself away. Like many others, I’ve blown hours doing nothing of value (to my bank account, anyway) while careening from one serendipitous encounter to another.

Put differently, Facebook can tend to reinforce existing relationships while making it more difficult to see what is happening with your weaker acquaintances. Other platforms, like Twitter, update their feeds differently and may allow users to see what is happening with their weak ties.

Of course, this all assumes that such online relationships are often instrumental, meant to help users acquire resources of one kind or another through a network.

Narratives built around the sociological “small world theory” of social networks

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A review of a new novel highlights recent ideas in the sociological analysis of social networks:

In sociology, the “small world theory” holds that any two people can be connected to one another along a chain of no more than a few acquaintances (typically six, the fabled “six degrees of separation”). Though the research behind it is at best contentious, there’s something deeply appealing about its logic-defying simplicity, something exciting about what it implies. In a world that can seem vast and alienating, the idea that we’re all much closer than it seems is, at first glance, comforting. The flip side is that our influence may extend further than we realize.

In his second novel, “The Illusion of Separateness,” Simon Van Booy presents a cast of characters who have had a profound effect on one another’s lives, yet cannot see the bonds that link them. He divides his book into six separate narratives, each following a different character through different eras, from the Second World War to the present: Martin, a retirement home caretaker; Mr. Hugo, a disfigured Wehrmacht veteran; Sébastien, a lovelorn young boy; John, whose B-24 bomber is shot out of the sky over France; Amelia, a blind museum curator and John’s granddaughter; and Danny, a budding filmmaker. Van Booy presents their stories in a nonlinear fashion, shifting back and forth from character to character, decade to decade.

Van Booy’s premise — that we are all linked in ways we may not fully understand, and that our smallest actions can have a significant effect on the lives of others — is fairly banal, and its execution verges on overly sentimental. He builds to the scenes in which his characters cross paths with great ceremony, yet these intersections are the book’s weakest moments. While the plot seems to aspire to present an overarching sense of meaning, Van Booy never quite drives it home. For some, the significance is inscrutable, as when John and Mr. Hugo engage in a tense, but ultimately inconsequential standoff in a field in war-torn France. Others, like when Martin cradles the dying Mr. Hugo in the book’s opening pages, seem like contrivances meant to give the narrative the appearance of structure and meaning.

For more popular descriptions of recent sociological research on this topic, see Six Degrees by Duncan Watts, Connected by Nicholas Christakis and James Fowler, and Linked by Barabasi (a physicist who covers a lot of ground).

This kind of narrative involving interweaving stories is not new. It seems to be popular in movies in the last 10-15 years – I’m thinking of films like Crash, Love Actually, and others that make use of intersecting characters. This leads to two thoughts:

1. Is this a good instance of social science discoveries, that social networks influence people without their knowledge, influencing popular culture? It could be relatively easy to track whether this is a new kind of plot or whether it has a longer history.

2. The reviewer suggests that while the author has impressive prose, the overall structure of the story is lacking. Since we do indeed live in social worlds strongly influenced by social networks, how can that be effectively translated into a compelling narrative? Going back to the movies I mentioned above, those intersecting storylines involved quite a bit of individual or small group interaction by the end of the movie. In contrast, this book seems to be going for a more disconnected set of stories. Setting up the structure of a social network narrative likely involves balancing the connections alongside the individual interactions that tend to characterize and propel narratives.

Viewing cities as crosses between stars and social networks

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A new paper from a physicist suggests cities are “social reactors,” somewhere between social networks and stars:

Others have suggested that cities look and operate like biological organisms, but that is not the case, says Bettencourt. “A city is a bunch of people, but more importantly, it’s a bunch of people interacting, so hence the social network,” he explains. “What’s important are the properties of this social network: the scaling was giving us clues. But then when you think of this superlinearity, which means the socioeconomic outputs are the result of those interactions, are expressed as growing superlinear functions of populations, the only system that I could think of in nature is a star. A star does have this property – it’s essentially a nuclear reactor sustained by gravity and shines brighter (has greater luminosity) the larger its mass. So there’s a sense that this behavior that is sustained by and created by attractive interactions and whose output is proportional to rate of interactions, is what a city is and a star is, and so in that sense they are analogous.”…

The result is this “special social reactor” that adheres to four main assumptions about city dynamics and scaling:

1) There are “mixing populations”: basically, cities have attractive interactions and social outputs are the results of those, which leads to more social interactions.

2) There is “incremental network growth”: notably, the networks themselves and the supporting infrastructure develop gradually as the city grows. The infrastructure is decentralized as are the networks themselves. This is very different from an organism, says Bettencourt, whose internal “infrastructure” (analogous to a vascular system for example) develops basically all at once and has a centralized node.

3) “Human effort is bounded”: as he writes in his paper, “The increasing mental and physical demand from their inhabitants has been a pervasive concern to social scientists. Thus this assumption is necessary to lift an important objection to any conceptualization of cities as scale-invariant systems.” In other words, “The costs imposed on people by living in the city do not scale up,” he says, because as the number of social interactions increase, one doesn’t have to necessarily travel more to get to these interactions. “The city comes to you as it becomes denser,” he notes.

4) “Socioeconomic outputs are proportional to local social interactions”: this gives us an interesting snapshot of exactly what a city is – not just a conglomeration of individuals, but rather a concentration of social interactions.

Sounds interesting. Cities are both agglomerations of social interactions as well as have unique infrastructures (physical and social) that gives shape to and is shaped by these interactions.

Five experts weigh in on global flight-path maps

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An art critic, environmentalist, aviation consultant, data visualization expert, and philosopher offer some interpretations of global flight-path maps.

From the art critic:

It’s almost like contemporary fractalisation – based on fractals, those beautiful divisions of science and nature. A number of artists have exploited them. Max Ernst based a lot of his surreal landscapes on fractalisation.

From the aviation consultant:

Europe looks so bright because it has so many short-haul flights. It’s also one of the busiest global markets and there are several hubs in relatively close proximity in Europe: Paris, Frankfurt, Amsterdam and London…

What we’re going to see in a few years is more connections between Asia and Africa, and South America and Africa, along with more “south-south” trade.

From the expert in data visualization:

You can see the density of the flights, but it doesn’t show you how many people are travelling on them. You could do that by colouring them differently.

From the philosopher:

We are not seeing the life of individual human beings, but the life of the species as a whole, as if the species was one organism, pulsating like a jellyfish. Maybe it represents our collective existence?

Interesting thoughts all around. The quote above from the philosopher is right on in that maps like these allows us to see larger patterns and how we are all connected. It is not just about the flow of passengers or cargo back and forth but also about how these flight paths connect us. The maps could also serve as a proxy for global power and business activity. I remember seeing work from sociologist Zachary Neal along these lines. Take a look at his publications involving cities, networks, and airplanes here.

The cities at the top of the global power hierarchy

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The 2013 Wealth Report Global Cities Survey ranks the top cities in the world in terms of power:

The survey was launched in 2008 to monitor city-level power shifts. Its objective is to assess the key urban centres across the world in terms of investment opportunities and the influence they have on global business leaders and decision makers…

Our Global Cities Survey’s four-part assessment of performance is designed to give the most rounded picture of the places that matter to the wealthy and influential. The survey focuses on four categories: economic activity; political power; quality of life; and knowledge & influence.

While New York and London hold on to the top two spots, the Asia-Pacific region, with four entries, has the tightest grip on the top 10. Europe and North America also feature, with three cities each. The Middle East’s first entry, Dubai, is at number 29, while South America’s leading cities, Buenos Aires and Sao Paulo, only just scrape into our top 40.

New York’s strength is reflected in its consistent showing across all four of our categories. The city is particularly strong in economic activity (being the wealth and financial centre for the world’s richest economy undoubtedly helps) and knowledge & influence, where the power of US media firms shines through. Indeed, there is a close relationship between economic activity and overall ranking, with New York, London, Paris and Tokyo occupying the top four slots for both.

When we turn to political power, Washington DC unsurprisingly leads the field, followed by Beijing and then Brussels – a small city in many ways, but one that punches above its weight politically as the headquarters of the European Union. Berlin sits just one place lower down, highlighting the growing tensions within the world’s largest economic bloc.

Here is a chart of the top five cities in each category:

This list doesn’t seem too different from the one A.T. Kearney released last year.

What would be nice to see in addition to these rankings is the interaction between these cities. For examples, how much do the social networks of the wealthy overlap across these places? How many corporations and organizations do significant business in each place? How is wealth actually spread across these places? I assume there are some significant patterns here but the emphasis in these lists is to still see these cities as separate places representing different countries.

Social network of email between countries shows homophily between culturally similar nations

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A new study of email traffic between countries finds some patterns:

The Internet was supposed to let us bridge continents and cultures like never before. But after analyzing more than 10 million e-mails from Yahoo! mail, a team of computer researchers noticed an interesting phenomenon: E-mails tend to flow much more frequently between countries with certain economic and cultural similarities.

Among the factors that matter are GDP, trade, language, non-Commonwealth colonial relations, and a couple of academic-sounding cultural metrics, like power-distance, individualism, masculinity and uncertainty…

To this point, of course, the study amounts to little more than very interesting trivia. The real conclusion comes toward the end, when the researchers posit it as possible evidence for Samuel Huntington’s controversial “Clash of Civilizations” theory. From the paper:

In this respect we cautiously assign a level of validity to Huntington’s contentions, with a few caveats. The ?rst issue was already mentioned – overlap between civilizations and other factors contributing to countries’ level of association. Huntington’s thesis is clearly re?ected in the graph presented in Figure 3, but some of these civilizational clusters are found to be explained by other factors in Table 5. The second limitation concerns the fact that we investigated a communication network. There is no necessary “clash” between countries that do not communicate, and Huntington’s thesis was concerned primarily with ethnic con?ict.

Interesting what can be done with data from more than 10 million emails.

I wonder if it is even worth doing this analysis at the country level. Isn’t this too broad? Aren’t there likely to be important patterns within and across countries that are obscured by this broader lens?

Another possible issue: is Yahoo mail a representative sample of emails or does it provide a particular slice of of email traffic? I would assume it involves more personal email as opposed to business activity.