Showing posts with label city. Show all posts
Showing posts with label city. Show all posts
Monday, July 8, 2013
Tuesday, February 19, 2013
The Happiest Cities in America, According to 10 Million Tweets
They also found that the Bible belt stretching across the American south and into Texas was less happy than the west or New England. The saddest town of the 373 urban areas studied was Beaumont in east Texas. The happiest was Napa, California, home of many drunk people wine makers. The only town among the 15 saddest that was not in the south or Rust Belt was Waterbury, Connecticut. (Although Waterbury has appeared on several "worst places to live" lists, which seems like mean lists to make.)
http://www.theatlanticcities.com/technology/2013/02/happiest-cities-america-according-10-million-tweets/4737/
http://www.theatlanticcities.com/technology/2013/02/happiest-cities-america-according-10-million-tweets/4737/
Monday, February 11, 2013
Thursday, February 7, 2013
Wednesday, January 30, 2013
Friday, January 11, 2013
How Economic Segregation Spreads Crime Like a Virus
In my last blog post, I wrote about how much we may be able to learn about effective crime prevention by comparing experiences across cities. The following week, I had a fascinating exchange with Richard Florida about which elements of city life are most important in preventing crime.
Our discussion prompted me to take a step back and ask: “What is the most important element of a place with respect to crime and public safety?” To answer, I’d like to conduct a thought experiment showing that economic segregation leads to the worst crime outcomes and that the best way to reduce crime is to find ways for the rich and poor to live next to each other. This is not based on some utopian fantasy, but rather on logic.
Crime is contagious. Of that, there is little doubt. A central predictor of crime levels in a neighborhood is how much crime there is in the neighborhood next door. Communities that share borders share crime (technically, this is known as spatial autocorrelation).
Over the past few decades, criminologists have become convinced that places can make people more crime-prone than they otherwise would be. Fix the place, and the people will be safer. For instance, a place with lots of alcohol outlets will almost certainly have more violence than an otherwise identical place with few places to buy liquor.
The best analogy is the spread of a virus. Each individual exposed to a virus has some chance of getting sick, but those with weaker immune systems have a greater risk of falling ill. Places bear similar risks. Certain features—poverty, density, isolation—put some places at greater risk of more crime and violence.
Here is the thought experiment: Suppose we set up the worst-case scenario, one where cities have no recourse to reduce crime other than arranging where people live. And suppose a city was assigned a set number of high-risk (economically disadvantaged) places, a set number of low-risk (highly prosperous) places, and some in between. Now we ask, how should the city arrange those places to create the most safety and the least amount of crime?
The answer is surprising. While we know that isolating our poorest residents is really bad for them, it turns out that segregating the rich and poor leads to the worst outcomes for a city as a whole. Economic integration, where the rich and poor live side by side, leads to the safest cities.
To test this hypothesis, I have borrowed some Brookings Institution models describing the spread of viruses. Working with our D.C. Crime Policy Institute, the Brookings scholars determined that at least 70 percent of crime in Washington, D.C., is due to contagion (the spreading of crime like an epidemic).
How does that work? Below, I describe a city as a 10 X 10 grid. Each of the 100 cells in the grid is a neighborhood. The neighborhoods have some intrinsic ability to fight a crime infection. The dark shaded areas are the most isolated, poorest, densest neighborhoods—and for this very stylized model, I assume they are all infected with the crime bug. The in-between areas (the lightly shaded areas) have a 25 percent chance of becoming infected if they are "exposed" to a neighboring community with high crime. The prosperous neighborhoods (the unshaded areas) are far more resilient; they only have a 5 percent chance of being infected if exposed.
First, let’s consider a perfectly segregated city. All the high-crime neighborhoods are in the same part of the city. All the prosperous places are physically isolated from the high-crime places by the in-between neighborhoods.
Now, let’s explore how an epidemic spreads. Below, we look at a section of our city where the infected places interact with their healthier neighbors. Infected neighborhoods are identified with a number, the in-between neighborhoods with a letter, and the prosperous areas are blank.
I assume there is a one-in-four chance that a high-crime neighborhood will infect its next-door neighbor, and thus every fourth "in-between" neighborhood touching an infected neighborhood becomes infected itself. Place 1 touches place A and place B. Place 2 also touches place A and B, so place B is the fourth neighborhood touched, meaning it becomes infected. Following this pattern, the bold letters below indicate the neighborhoods that become infected.
Place 1—A, B
Place 2—A, B, C
Place 3—B, C, D
Place 4—C, D, E
Place 5—D, E, F, G, H. (Since place D is already infected, we’ll just mark place E as infected in the grid below to properly show the crime bug’s reach).
So, on our first pass, we see four new places infected with crime.
Now, places B, D, E, and H are sick, with a 25 percent chance of infecting their neighboring communities, and so on.
When you work through the entire epidemic, you find that the 25 infected neighborhoods infect an additional 17 neighborhoods. By segregating and isolating the most at-risk places, crime is not corralled, but rather spreads more effectively.
Now imagine that instead of surrounding the infected places with in-between places, we instead surround the infected places with the most prosperous places. Since only 1 in 20 (5 percent) of prosperous places is infected when exposed to the crime virus, then only one prosperous neighborhood is infected in this thought experiment.
Thus, having rich and poor live side by side means 26 of our 100 neighborhoods have crime problems. That is a vast improvement to absolute segregation, where 42 of our 100 neighborhoods are infected.
Of course, this thought experiment ignores the positive benefits of vaccinating places. Cities have many potential vaccines in their arsenal to prevent the spread of a crime epidemic. Identifying which vaccines are most effective is at the core of the discussion Florida and I began about which elements of city life are most important in preventing crime. But it is helpful to begin that discussion by framing it in terms of contagion, epidemics, and vaccines.
The bottom line is, just as we cannot arrest our way out of crime problems, we also cannot economically segregate and isolate our way out either. That approach is self-destructive and has led to many of the problems our cities face today. Figuring out how to fix those mistakes is at the core of creating prosperous places.
Our discussion prompted me to take a step back and ask: “What is the most important element of a place with respect to crime and public safety?” To answer, I’d like to conduct a thought experiment showing that economic segregation leads to the worst crime outcomes and that the best way to reduce crime is to find ways for the rich and poor to live next to each other. This is not based on some utopian fantasy, but rather on logic.
Crime is contagious. Of that, there is little doubt. A central predictor of crime levels in a neighborhood is how much crime there is in the neighborhood next door. Communities that share borders share crime (technically, this is known as spatial autocorrelation).
Over the past few decades, criminologists have become convinced that places can make people more crime-prone than they otherwise would be. Fix the place, and the people will be safer. For instance, a place with lots of alcohol outlets will almost certainly have more violence than an otherwise identical place with few places to buy liquor.
The best analogy is the spread of a virus. Each individual exposed to a virus has some chance of getting sick, but those with weaker immune systems have a greater risk of falling ill. Places bear similar risks. Certain features—poverty, density, isolation—put some places at greater risk of more crime and violence.
Here is the thought experiment: Suppose we set up the worst-case scenario, one where cities have no recourse to reduce crime other than arranging where people live. And suppose a city was assigned a set number of high-risk (economically disadvantaged) places, a set number of low-risk (highly prosperous) places, and some in between. Now we ask, how should the city arrange those places to create the most safety and the least amount of crime?
The answer is surprising. While we know that isolating our poorest residents is really bad for them, it turns out that segregating the rich and poor leads to the worst outcomes for a city as a whole. Economic integration, where the rich and poor live side by side, leads to the safest cities.
To test this hypothesis, I have borrowed some Brookings Institution models describing the spread of viruses. Working with our D.C. Crime Policy Institute, the Brookings scholars determined that at least 70 percent of crime in Washington, D.C., is due to contagion (the spreading of crime like an epidemic).
How does that work? Below, I describe a city as a 10 X 10 grid. Each of the 100 cells in the grid is a neighborhood. The neighborhoods have some intrinsic ability to fight a crime infection. The dark shaded areas are the most isolated, poorest, densest neighborhoods—and for this very stylized model, I assume they are all infected with the crime bug. The in-between areas (the lightly shaded areas) have a 25 percent chance of becoming infected if they are "exposed" to a neighboring community with high crime. The prosperous neighborhoods (the unshaded areas) are far more resilient; they only have a 5 percent chance of being infected if exposed.
First, let’s consider a perfectly segregated city. All the high-crime neighborhoods are in the same part of the city. All the prosperous places are physically isolated from the high-crime places by the in-between neighborhoods.
Now, let’s explore how an epidemic spreads. Below, we look at a section of our city where the infected places interact with their healthier neighbors. Infected neighborhoods are identified with a number, the in-between neighborhoods with a letter, and the prosperous areas are blank.
I assume there is a one-in-four chance that a high-crime neighborhood will infect its next-door neighbor, and thus every fourth "in-between" neighborhood touching an infected neighborhood becomes infected itself. Place 1 touches place A and place B. Place 2 also touches place A and B, so place B is the fourth neighborhood touched, meaning it becomes infected. Following this pattern, the bold letters below indicate the neighborhoods that become infected.
Place 1—A, B
Place 2—A, B, C
Place 3—B, C, D
Place 4—C, D, E
Place 5—D, E, F, G, H. (Since place D is already infected, we’ll just mark place E as infected in the grid below to properly show the crime bug’s reach).
So, on our first pass, we see four new places infected with crime.
Now, places B, D, E, and H are sick, with a 25 percent chance of infecting their neighboring communities, and so on.
When you work through the entire epidemic, you find that the 25 infected neighborhoods infect an additional 17 neighborhoods. By segregating and isolating the most at-risk places, crime is not corralled, but rather spreads more effectively.
Now imagine that instead of surrounding the infected places with in-between places, we instead surround the infected places with the most prosperous places. Since only 1 in 20 (5 percent) of prosperous places is infected when exposed to the crime virus, then only one prosperous neighborhood is infected in this thought experiment.
Thus, having rich and poor live side by side means 26 of our 100 neighborhoods have crime problems. That is a vast improvement to absolute segregation, where 42 of our 100 neighborhoods are infected.
Of course, this thought experiment ignores the positive benefits of vaccinating places. Cities have many potential vaccines in their arsenal to prevent the spread of a crime epidemic. Identifying which vaccines are most effective is at the core of the discussion Florida and I began about which elements of city life are most important in preventing crime. But it is helpful to begin that discussion by framing it in terms of contagion, epidemics, and vaccines.
The bottom line is, just as we cannot arrest our way out of crime problems, we also cannot economically segregate and isolate our way out either. That approach is self-destructive and has led to many of the problems our cities face today. Figuring out how to fix those mistakes is at the core of creating prosperous places.
Wednesday, January 2, 2013
What City Skies Would Look Like Without Light Pollution
Ground Zero
Artist Thierry Cohen
http://thierrycohen.com/pages/work/starlights.html
Ground Zero
Artist Thierry Cohen
http://thierrycohen.com/pages/work/starlights.html
Thursday, December 20, 2012
Race, unfortunately and tragically, factors into gun death at the metro level. The share of the population that is black is positively related to both the overall rate of gun death (.56) and even more so with gun-related homicides (.72). The pattern is similar for the share of the population that is comprised of young black males which is also positively related to the overall rate of gun death (.55) and murder by gun (.70). That said, we find no significant association between any type of gun death and the share of the population that is Hispanic. The importance of gun control cannot be minimized. The state level is the appropriate level to examine this. And our previous state level analysis found gun deaths to be significantly lower in states with stricter gun control laws.
The rate of gun deaths is negatively correlated with states that ban assault weapons, require trigger locks, and mandate safe storage requirements for guns.
Death by gun clearly reflects the class divides which vex America, being substantially more likely in poorer, less advantaged places. And this concentrated nature of gun violence makes it easier for those in more affluent and sheltered places to ignore its consequences. Yes, our nation is in desperate needs of strategies to bridge its burgeoning class divide, but if we truly care to limit the carnage caused by guns in our society, controlling them is the best place to start.
Friday, August 3, 2012
How Urban Parks Enhance Your Brain, Part 2
Our results showed that perceived restorativeness in urban forests was strongly affected by closure of view to the urban matrix through the forest vegetation. This means that perceived restorativeness was higher inside the forest with a closed (i.e. no) view to the urban matrix as compared to semi-closed and open views.
The most intriguing conclusion to be drawn here is that the size of an urban park isn't nearly as important as the density of its vegetation. Even when a nature site borders an urban road or housing development, it can function as a restorative place so long as it offers easy access to a dense interior. In other words, the ultimate goal is not to see the city for the trees.
-The Atlantic Cities
The most intriguing conclusion to be drawn here is that the size of an urban park isn't nearly as important as the density of its vegetation. Even when a nature site borders an urban road or housing development, it can function as a restorative place so long as it offers easy access to a dense interior. In other words, the ultimate goal is not to see the city for the trees.
-The Atlantic Cities
Tuesday, July 31, 2012
The Case for More Urban Trees
*The net cooling effect of a young, healthy tree is equivalent to ten room-size air conditioners operating 20 hours a day.
*If you plant a tree today on the west side of your home, in 5 years your energy bills should be 3 percent less. In 15 years the savings will be nearly 12 percent.
*One acre of forest absorbs six tons of carbon dioxide and puts out four tons of oxygen.
*A number of studies have shown that real estate agents and home buyers assign between 10 and 23 percent of the value of a residence to the trees on the property.
*Surgery patients who could see a grove of deciduous trees recuperated faster and required less pain-killing medicine than matched patients who viewed only brick walls.
*In one study, stands of trees reduced particulates by 9 to 13 percent, and the amount of dust reaching the ground was 27 to 42 percent less under a stand of trees than in an open area.
Among other things, he calculated that "for a planting cost of $250-600 (includes first 3 years of maintenance) a single street tree returns over $90,000 of direct benefits (not including aesthetic, social and natural) in the lifetime of the tree."
Street trees create slower and more appropriate urban traffic speeds, increase customer traffic to businesses, and obviate increments of costly drainage infrastructure. In at least one recent study (reported after Burden’s analysis), trees were even found to be associated with reduced crime.
I think some of the most important benefits, though, are felt emotionally. Burden puts it this way:
~Urban street trees provide a canopy, root structure and setting for important insect and bacterial life below the surface; at grade for pets and romantic people to pause for what pets and romantic people pause for; they act as essential lofty environments for song birds, seeds, nuts, squirrels and other urban life. Indeed, street trees so well establish natural and comfortable urban life it is unlikely we will ever see any advertisement for any marketed urban product, including cars, to be featured without street trees making the ultimate dominant, bold visual statement about place.~
Source
Friday, July 27, 2012
Segregation Curtailed in U.S. Cities
Segregation Curtailed in U.S. Cities, Study Finds
By SAM ROBERTS
William H. Frey, the chief demographer at the Brookings Institution, cautioned that “the report sends a potentially harmful message that black-white residential separation is no longer a priority issue in this country.
“While recent modest declines in black segregation levels are welcome, the 2010 census shows that the average black resident still lives in a neighborhood that is 45 percent black and 36 percent white,” he said. “At the same time, the average white lives in a neighborhood that is 78 percent white and 7 percent black. Black segregation levels are even higher for children, signaling the continued separation of black and white families across communities with different levels of resources available for schools and other services important for nurturing the next generation.”
John R. Logan, a Brown sociologist, said: “If we want to understand the long-term trends in segregation, we have to be aware both of the progress and of the resistance to change. We are far from the ‘end of segregation.’ ”
Still, Professors Glaeser and Vigdor found that only 20 percent of blacks now live in “ghetto” neighborhoods where 80 percent of the population or more is black, compared with nearly 50 percent who lived in similar neighborhoods a half-century ago.
The findings in the report, titled “The End of the Segregated Century,” for the Manhattan Institute’s Center for State and Local Leadership did not denigrate decades of desegregation efforts. In fact, the authors said, “there is every reason to relish the fact that there is more freedom in housing today than 50 years ago and to applaud those who fought to create the change.” But they concluded that housing desegregation was not a magic bullet in providing equal opportunity.
“Residential segregation has declined pervasively, as ghettos depopulate and the nation’s population center shifts toward the less segregated Sun Belt,” Professors Glaeser and Vigdor wrote. “At the same time, there has been only limited progress in closing achievement and employment gaps between blacks and whites.”
The study’s definition of neighborhood was borrowed from the census: a tract that is home to 1,500 to 7,500 people. The analysis relied on the two most common segregation indexes: dissimilarity, or the proportion of individuals of either group that would have to switch neighborhoods to achieve perfect integration, and isolation, which measures neighborhoods where the share of the population of one group surpasses the citywide average.
By the dissimilarity index, Dallas and Houston are the least segregated big cities.
Los Angeles fared best on the isolation index.
Among cities with the largest black population, Chicago, Cleveland, Detroit and St. Louis ranked highest in the dissimilarity index. Among metropolitan areas, Chicago, New York and Philadelphia did.
Since 1960, the share of blacks living in neighborhoods where they account for a minority of the population has risen to 59 percent from 30 percent.
“While it may be tempting to see the overwhelmingly white nature of many suburbs as evidence of stagnation or stasis, the presence of even modest numbers of African-Americans in suburbs demonstrates the remarkable change in American society,” the study said. “Indeed, measured by dissimilarity indices, suburbs are often among the most integrated parts of America.”
Only 424 of the nation’s 72,531 census tracts recorded no black residents. More than half were either in rural areas or in metropolitan regions where blacks account for less than 1 percent of the population. Every census tract in Connecticut, Maryland and New Hampshire recorded at least one black resident.
By SAM ROBERTS
William H. Frey, the chief demographer at the Brookings Institution, cautioned that “the report sends a potentially harmful message that black-white residential separation is no longer a priority issue in this country.
“While recent modest declines in black segregation levels are welcome, the 2010 census shows that the average black resident still lives in a neighborhood that is 45 percent black and 36 percent white,” he said. “At the same time, the average white lives in a neighborhood that is 78 percent white and 7 percent black. Black segregation levels are even higher for children, signaling the continued separation of black and white families across communities with different levels of resources available for schools and other services important for nurturing the next generation.”
John R. Logan, a Brown sociologist, said: “If we want to understand the long-term trends in segregation, we have to be aware both of the progress and of the resistance to change. We are far from the ‘end of segregation.’ ”
Still, Professors Glaeser and Vigdor found that only 20 percent of blacks now live in “ghetto” neighborhoods where 80 percent of the population or more is black, compared with nearly 50 percent who lived in similar neighborhoods a half-century ago.
The findings in the report, titled “The End of the Segregated Century,” for the Manhattan Institute’s Center for State and Local Leadership did not denigrate decades of desegregation efforts. In fact, the authors said, “there is every reason to relish the fact that there is more freedom in housing today than 50 years ago and to applaud those who fought to create the change.” But they concluded that housing desegregation was not a magic bullet in providing equal opportunity.
“Residential segregation has declined pervasively, as ghettos depopulate and the nation’s population center shifts toward the less segregated Sun Belt,” Professors Glaeser and Vigdor wrote. “At the same time, there has been only limited progress in closing achievement and employment gaps between blacks and whites.”
The study’s definition of neighborhood was borrowed from the census: a tract that is home to 1,500 to 7,500 people. The analysis relied on the two most common segregation indexes: dissimilarity, or the proportion of individuals of either group that would have to switch neighborhoods to achieve perfect integration, and isolation, which measures neighborhoods where the share of the population of one group surpasses the citywide average.
By the dissimilarity index, Dallas and Houston are the least segregated big cities.
Los Angeles fared best on the isolation index.
Among cities with the largest black population, Chicago, Cleveland, Detroit and St. Louis ranked highest in the dissimilarity index. Among metropolitan areas, Chicago, New York and Philadelphia did.
Since 1960, the share of blacks living in neighborhoods where they account for a minority of the population has risen to 59 percent from 30 percent.
“While it may be tempting to see the overwhelmingly white nature of many suburbs as evidence of stagnation or stasis, the presence of even modest numbers of African-Americans in suburbs demonstrates the remarkable change in American society,” the study said. “Indeed, measured by dissimilarity indices, suburbs are often among the most integrated parts of America.”
Only 424 of the nation’s 72,531 census tracts recorded no black residents. More than half were either in rural areas or in metropolitan regions where blacks account for less than 1 percent of the population. Every census tract in Connecticut, Maryland and New Hampshire recorded at least one black resident.
Thursday, July 26, 2012
Friday, July 20, 2012
The Cognitive Beneļ¬ts of Interacting With Nature
In sum, we have shown that simple and brief interactions with nature can produce marked increases in cognitive control. To consider the availability of nature as merely an amenity fails to recognize the vital importance of nature in effective cognitive functioning.
Earlier this year the same research group (with additional collaborators) came out with another study, set for publication in the November issue of the Journal of Affective Disorders. This time the researchers wondered how nature would influence a group of participants with clinical major depression. On one hand their symptoms could improve as attention and cognition were enhanced; on the other, their mood might worsen if they used the stroll through the woods to ruminate on troubling thoughts.
Just as before, attention performance increased more after nature walks than urban walks (in fact, the effect size was five times larger than in the 2008 study). The mood priming worked too: participants left the lab for their respective walks in worse moods than when they entered it. But after the strolls, those people who'd been through the park showed much greater improvement in "positive affect" — an emotional state typically low in depressed patients.
The study prompts several conclusions. The first, not really tied to cities, is that nature walks might provide a cost-efficient supplement to traditional treatments for major depression. As the researchers point out, the mood priming did work, meaning study participants set out on their journey thinking about a negative personal event. The fact that their positive affect improved despite this sour state shows the cognitive power of park land.
The second conclusion, more germane for our purposes, is that "incorporating nearby nature into urban environments may counteract" some of the cognitive strains placed on the brain by the city, the authors write. Recent research has suggested economic and crime benefits of urban greenery; now advocates can legitimately add "public health" to their list of arguments.
As always, caveats apply. To name just one: Nichols Arboretum in Ann Arbor, while no Central Park, is still quite vast at 123 acres. It would be nice to see the results replicated in an urban park of more modest (or, better yet, statistically average) proportions. Be great to know just how many trees it takes to give a city brain the break it needs from crossing traffic, or navigating subway platforms, or sitting in our cubicles reading Cracked.
http://www.theatlanticcities.com/arts-and-lifestyle/2012/07/how-urban-parks-enhance-your-brain/2586/
FULL REPORT: http://www.umich.edu/~jlabpsyc/pdf/2008_2.pdf
Earlier this year the same research group (with additional collaborators) came out with another study, set for publication in the November issue of the Journal of Affective Disorders. This time the researchers wondered how nature would influence a group of participants with clinical major depression. On one hand their symptoms could improve as attention and cognition were enhanced; on the other, their mood might worsen if they used the stroll through the woods to ruminate on troubling thoughts.
Just as before, attention performance increased more after nature walks than urban walks (in fact, the effect size was five times larger than in the 2008 study). The mood priming worked too: participants left the lab for their respective walks in worse moods than when they entered it. But after the strolls, those people who'd been through the park showed much greater improvement in "positive affect" — an emotional state typically low in depressed patients.
The study prompts several conclusions. The first, not really tied to cities, is that nature walks might provide a cost-efficient supplement to traditional treatments for major depression. As the researchers point out, the mood priming did work, meaning study participants set out on their journey thinking about a negative personal event. The fact that their positive affect improved despite this sour state shows the cognitive power of park land.
The second conclusion, more germane for our purposes, is that "incorporating nearby nature into urban environments may counteract" some of the cognitive strains placed on the brain by the city, the authors write. Recent research has suggested economic and crime benefits of urban greenery; now advocates can legitimately add "public health" to their list of arguments.
As always, caveats apply. To name just one: Nichols Arboretum in Ann Arbor, while no Central Park, is still quite vast at 123 acres. It would be nice to see the results replicated in an urban park of more modest (or, better yet, statistically average) proportions. Be great to know just how many trees it takes to give a city brain the break it needs from crossing traffic, or navigating subway platforms, or sitting in our cubicles reading Cracked.
http://www.theatlanticcities.com/arts-and-lifestyle/2012/07/how-urban-parks-enhance-your-brain/2586/
FULL REPORT: http://www.umich.edu/~jlabpsyc/pdf/2008_2.pdf
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