New study sheds light on roadway safety for all

Traffic safety has been one of those long-standing fault lines in the purported war between cars and pedestrians. In the one corner, we have traffic engineers who are given the task of designing roadways to maximize speed and capacity, while maintaining what is considered an acceptable level of safety for motorists. You do this by making the roadway as forgiving as possible with wider lanes, longer sight distances, and nothing to crash into along the side of the road. In the other corner, pedestrian advocates have insisted on slowing cars down with traffic calming, on-street parking, pedestrian signal prioritization and lots of other strategies to look after their own safety. As the story goes, each side is locked in a shouting match over whose safety is the most important.

Design Solutions for Balancing Traffic Conflicts and Speed. Source: Dumbaugh et. al.

But a new study that appears in the Journal of the American Planning Association sheds more light than heat on the subject. Eric Dumbaugh and Wenhau Li found that designs that make the travel safer for any road user make travel safer for every road user. Really, there is no zero sum game. We don’t have to pick one team. Thankfully.

The researchers looked at almost 300,000 crashes in the San Antonio area and considered all of the details of where the crash happened, not just how many cars use the road or how wide the lanes are. They asked: Is this a pedestrian-scaled “Main Street” or is it an arterial lined with strip malls? Are there big box stores around? How many intersections are in the area, and how many people live nearby? Then they considered who was involved in the crash. Two vehicles? A vehicle and cyclist? A vehicle and a tree? With all of these variables in mind, they determined which factors were better correlated with a safer environment … and for whom.

The results may not entirely satisfy either side, but they make sense. Freeways turn out to be pretty safe, showing a relatively small proportion of crashes. This probably has more to do with the lack intersections on highways, than it does the opulent shoulders and smooth grades. With access limited to a few exits and entrances, there are just fewer chances to collide with an oncoming vehicle. But just as the highway engineers may consider theories are vindicated, the research shows that places on the opposite end of the spectrum are just as safe.

“The presence of pedestrian-scaled retail uses, on the other hand, was associated with significant reductions in multiple-vehicle, parked-car, fixed-object, and pedestrian crashes. We attribute this to reduced vehicle speeds. Street oriented buildings create a sense of visual enclosure of the street, communicating to the driver that greater caution is warranted, and resulting in reductions in both vehicle speed and crash incidence.”

Consider all of the chaos of a Main Street scene. A driver is trying to parallel park while a cyclist dodges the opening door. Pedestrians are crossing at will, and delivery trucks are backing into their spaces.  Visual stimulation is everywhere. The old engineering models would take all of these inputs and calculate a daily bloodbath, but nothing of the sort is happening. It’s a highly functional environment. The key here is that both the Main Street and the Freeway are relatively safe for all road users, motorists and pedestrians alike (although let’s admit that pedestrian safety on the freeway is purely a function of their non-existence).

The absolute worst places for everyone were the ones that fell between the cracks of the two paradigms. There’s one of these in your town. The wide highway with a traffic light every few hundred feet leading into strip shopping centers. They are designed to be Freeway-esque with plenty of room for you to veer out of your lane, yet with all of the conflicts of cars pulling in and out still there. These precautions are just a cruel trick, inducing drivers to take on more speed than they really should to their own detriment. Pedestrians are caught in the cross-fire with no armor, and before you judge them for having the audacity just to be there, remember that many service-sector workers have no choice. In the twentieth century we dreamed of the best of both words for our roadways – access and speed! - but ended up with the worst of both worlds.

Freeways will still be utilized for those long-distance trips between cities, at least while gas is still relatively inexpensive. They should continue to be designed to handle the high speeds they command, to allow drivers to travel safely. But within highly-concentrated urban areas, mindlessly applying these same standards wrecks havoc. In these cases, a design approach that takes into account the whole context of the street yields a much safer result for pedestrians and motorists alike.

Where does a revolution happen?

In an historic sequence of events for the nation of Egypt, massive demonstrations were held at the Nile View mall in suburban Cairo. Protesters began gathering outside of J.C. Penney in late January. Within a week the parking lot was full, and traffic was backed up for miles with eager activists waiting to enter. The food court was taken over as a makeshift shelter, and new vendors popped up to compete with Sbarros and Panda Express to feed the demonstrators. When Hosni Mubarak agreed to step down, the elated crowds moved into the multiplex movie theater for celebration. Historians believe this may be the first revolution in world history entirely set to the soundtrack of smooth jazz.

No, wait. None of this is happening.

Photo taken by Flickr user Ramy Raoof

Democracy for the nation of Egypt was won in Tahrir Square, right in the heart of Cairo. Tahrir Square is surrounded by museums, governmental offices, universities, stores and hotels, and many, many compact neighborhoods, making it a natural epicenter of human activity and the obvious site for political action. Being one of the mostly densely populated cities in the world, thousands of protestors can converge in the center and meet with others from across the socio-economic range. Protestors flooded into the square through the Egypt Metro system, one of the busiest in the world. Although authorities tried to quell the demonstration by blocking the square’s Metro stop, many of the participants have been getting off at nearby stops and walking the rest of the way in.

Edward Glaeser pointed out in the New York Times last week that “it’s always the urban pot that boils over.” Cairo, Egypt and Tunis, Tunisia are only the latest installments in the tumultuous story of cities.

“Cities are places of revolution, because urban proximity connects organizers of opposition. Large urban populations create the scale needed to initially overwhelm local law enforcement … The constant interaction of human energy in dense clusters creates innovations in every area of human life, including politics.”

All the tweets and texts flying through the airwaves have not changed the fact that a physical place, a public square in the most literal sense, will always be a necessary stage for any kind of action. You know, in reality.

Here’s Sarah Goodyear writing in Grist,

“The government of Hosni Mubarak could shut down the internet. It could shut down cell phone service. It could force Al Jazeera, which has been providing superb coverage of the events in Egypt, to close its Cairo bureau. It could arrest journalists and seize their equipment.

But the streets of Cairo themselves have been the medium that has carried the message of the Egyptian people. So have the streets of Alexandria, Suez, and other Egyptian cities. And the government's efforts to keep people off those streets have failed completely."

And Tahrir Square was not just a convenient place to hold a rally. Hey, we're about equidistant between most of our homes, plenty of space to work with, let's start gathering here. No, the fact that the message was brought to the center of the capital city itself conveyed meaning. The central public square is likewise the impromptu location for celebration.

Michael Sandel on public places

                                                            Source: Harvard Gazette

I was pleased to see Michael Sandel’s name show up as a keynote speaker at this year’s American Planning Association conference. He’s a well-known Harvard political philosopher who has made a career out of pushing the boundaries of how we talk about right and wrong toward the notion of the common good. But what does high-minded ethical reasoning have to do with planning the places we live in? As I would find out, quite a bit.

I turned to Sandel’s most recent book, Justice: What’s the Right Thing to Do, based on a course he’s taught for the last two decades (which happens to also be a hit on Japanese TV, oddly enough). It’s jam packed with those thorny moral dilemmas that are great fun to subject your friends to. After running through the answers given by the usual suspects throughout history, he finishes out the book with his own position. Here’s one salient point:

“An earlier generation made a massive investment in the federal highway program, which gave Americans unprecedented mobility and freedom, but also contributed to a reliance on the private automobile, suburban sprawl, environmental degradation, and living patterns corrosive to community. This generation could commit itself to an equally consequential investment in an infrastructure for civic renewal: public schools for which rich and poor alike would want to send their children, public transportation systems reliable enough to attract upscale commuters; public health clinics, playgrounds, parks, recreation centers, libraries, and museums that would, ideally at least, draw people out of their gated communities and into the common spaces of a shared democratic citizenship.”

To see how he lands here, we’ll have to back up a little to grasp the underlying principles. Sandel calls into the question the modern notion of grounding all of ethics in the consent of individuals, instead reaching back to Aristotle and the notion of a civic order that encourages a strong character that looks outward from itself. Asking anyone today to honor the public good seems even a little quaint, and cynics are ever looking for the angle, but Sandel is serious about reviving the calling of citizenship.

He notes that our public discourse has come to revolve almost entirely around personal rights and personal demands. On the right, this means defending the economic decisions to buy and sell as you wish. On the left, it means breaking away from the shackles of traditional social mores and leveling inequalities. Your choices are: either let everyone keep the resources they earn in the marketplace or redistribute resources to the individuals who have more of a need. But both sides seem to agree that we are essentially individuals. We may engage in relationships or associate ourselves with certain groups, but only as long as our personal goals are achieved in the process.

How does this philosophy translate into our physical places? It means big private homes and small public spaces, many yards and few parks, lots of driving alone and little public transportation, gated communities with or without the literal gates – basically a whole place arranged so that we will never have to see a neighbor or a stranger unless we specifically choose to. We could say all sorts of things about the fairness or sustainability of this arrangement, but Sandel raises another point. This kind of place makes it harder for us to build the character traits we look up to: courage, solidarity to a community, mutual respect, sacrifice for the good of others. You can’t just read about being a good person. It takes some training and a practice field.

To pluck a story from the Christian tradition, when an injured Jewish traveler was lying along the side of a road, it was the Samaritan, his sworn ethnic enemy, who decided to lend a hand. This scene was Jesus’ response to the question “who is your neighbor?” We may like to think of ourselves as similarly generous, but we forget that the Samaritan had to actually walk past the injured man in the first place just to be presented with the dilemma.

This might be what Sandel means by an “infrastructure of civic renewal,” a full-bodied public realm that may be more challenging – alas, we don’t all agree about what the good life should be – but one that will strengthen us through the give and take of a wider community. And this can’t happen if we don’t build places to facilitate these interactions.

Framing the Ethics of Metropolitan Growth

Source: Continuum

I'll come right out and say that Ethics of Metropolitan Growth is a wonderful resource. Robert Kirkman is a philosopher employed in the realm of public policy by Georgia Tech, and he has obviously poured significant amounts of experience and reflection into this relatively short book. Without an ounce of jargon and very little academic name-dropping, it really is refreshing to read. He drills down to the basic questions of what we want out of the place we live in.

[By the way, please don't confuse my effusive praise for any compensated endorsement. That wouldn't be very ethical, would it?]

The book tours through many of the planning and design decisions we make in our communities, revealing the tangled knot of values and intentions that will be immediately recognizable to anyone who's been to more than a few public hearings or read through comment threads from the whole spectrum of websites. Complicated? Sure, yet he neither leaves us awash in moral ambiguity nor sets up any side in particular on the moral high ground, from which grenades of judgment can be lobbed on the opponents below. He simply builds a framework to help anyone sort through their own goals and compare them with the goals of others.

Kirkman's outlook on ethics, in general, is very modest. He accepts that every decision is uniquely determined by the situation it's embedded in, so no single rule can be applied across the boards to supply the right answer to a question. By extension, this means that blame (or praise) is often very difficult to discern. He also refuses to take sides on any of the perennial debates philosophers engage in over ethics. Is it the consequences of the action that counts? Is it the motivation behind the action that counts? Is it the character of the person acting that counts? All of the above, Kirkman says. He can do this, because he isn't really looking for a way to splice right from wrong but simply a way to think about right and wrong.

"The point is to ask critical questions about each view, to examine its scope and its limits. to test whether it holds together and whether it can be put into practice."

To be honest, this does come across as too modest for many topics. Most of us want to be able to conclude that raids on innocent villagers in the Darfur region of Sudan are flat-out evil, rather than suggest that the raider engage in some serious reflection over whether his intentions are internally consistent or not. But the book isn't about genocide. It's about zoning. And how to get to the store. The hushed, cerebral tone is completely appropriate. To the neighbor shouting down a greedy developer or the dude waiving a shotgun at anyone who will meddle with his property, Kirkman says: relax, let's think it through.

Source: Encyclopedia of Earth

So how do we do that? The framework he presents is better than anything out there. I've been taught a technique called the triangle of sustainability, otherwise known in business terms as the triple bottom line, for making planning decisions. I've always found it to be awkward. You're suppose to balance between economic development, environmental protection, and social equity, all under the banner of "sustainability" which then immediately buckles under the weight and collapses into utter meaninglessness. The terms are not well matched up to each other, and there's no real advice for actually making the trade-off (which is really the whole source of conflict). The triangle also doesn't touch on the important question of who should be making the decision anyway.

Kirkman's framework starts with a place-based spin on Aristotle's classic quest for the good life. Since our lives are necessarily shaped by the environment that surrounds us, the issue becomes whether a place either constrains us or enables us to seek the good. We won't all agree on what the good life is, but at least we can have some clarity on how the built environment overlaps with these personal goals. The second consideration is how the identified good is distributed among people. Is it fair? The third consideration is how the identified good is distributed through time. Will it last? Finally, there's the question of process.

Source: Ethics of the Built Environment

Consider the suburban ideal of living in a private, detached house halfway between nature and culture, possessing the best of both worlds. Those who embrace this as their preferred lifestyle could check off each item on the well-being list, but moving to justice and sustainability reveals some difficulties. If others were to follow suit and move into the neighborhood, the balance is upset toward density and it no longer feels so natural. Therefore, you impose regulations to exclude others, which should be problematic if you consider yourself a person who values fairness. And given that land and energy is finite and human population keeps growing, it's not at all clear that this arrangement will last. Do you want your grand-children to also enjoy this life? Here is the underlying contradiction behind the old joke: sprawl and density are the two things people hate most. The point of the framework is to force a resolution between these competing personal goals.

He doesn't let New Urbanists off the hook either, pointing out how often they present a false choice between an idealized traditional town and the most chaotic of modern suburbs. This is unnecessarily limiting. One of the points of engaging in the ethical exercise is to hunt for new possibilities that had previously been ruled out or missed entirely. It should spur creativity and reveal win-win solutions that meet the unstated preferences lurking beneath some of the stubborn public positions we take.

This is a good list, but I can't pass up griping about including mobility as basic to well-being. Most of us value getting to the place we want to go (accessibility), not just moving from one place to another (mobility). Achieving access usually includes mobility, but it also includes proximity, or not having to move very far to get to where you want to go. Although this seems like splitting hairs, setting access as the ultimate goal of a transportation system completely changes how performance is measured and projects are selected. Just had to throw that in.

One of the more intriguing discussions is over the legitimacy category, especially the scale of the decision. We don't act only as individuals, but also as groups. Even the most ardent libertarian will accept that sometimes decisions should be collectively made, even if he'll insist that this be voluntarily entered into (i.e. marriage, joining a Homeowners Association) and an eject button is readily available (i.e. divorce, leaving the HOA). The rest of us are even more comfortable with power vested in a range of organizations, as long as we are represented fairly in decisions the group makes.

As in the example to the left (my own), a similar inquiry can be broken down across different scales, typically matched with different ranges of time as well. Each expression exerts cause and effect on the rest, making it hard to pin-point any one as the ultimate reason for the way things are. Kirkman writes,

"To the extent all of the different ranges of government pull against one another, each asserting its own rights and prerogatives, there is less likely to be an effective response to problems in the built environment. Perhaps most important, there is often a mismatch between the scale of problems and the scale of government authority with the power to address them."

This leads him to point out the lack of effective regional bodies in American politics, not because a region is the optimal vantage point for all planning decisions but simply because it happens to be underrepresented. The issue of affordable housing is a classic regional problem. Almost everyone values a sufficient amount of housing affordable to residents with the range of incomes somewhere in their region, but the same people start having reservations about putting it in their own neighborhood, and few homeowners want to see their own  home become more affordable. Approaching this problem with too small a scale, and you get inefficient fragmentation; too large a scale, and you're apt to be insulated from what citizens actually want for their own community. For this particular question, the region seems just about right.

Kirkman is not so much of a philosopher to insist on subjecting every single decision to this level of scrutiny. He acknowledges that even stepping off the front porch, "I could find myself paralyzed, my foot poised eternally above the pavement, unable to take a single step while the deliberation goes on." Practically, we need to use reflexive behaviors and snap-judgments about the built environment. But the reader of this volume is treated to at least of a few hours of time to stand back and reflect on these habits of thought about the places we live in. It's a worthwhile exercise for any of us.

New Census numbers confirm the resurgence of cities

With the release of the new American Community Survey data on Tuesday, we are now able to see how the fine-grained nature of metropolitan areas has changed over the last few years. This is the first release since the 2000 Census that really provides enough detail to map these changes, and the New York Times has stepped up to the plate with a handy mapping tool. The Census American Factfinder website will get an upgrade in about a month, and mapping will be much easier once that happens.

Poking through some of the data, I haven't been able to discern any interesting new trends that have not previously been identified. But we do see some pretty clear confirmation of earlier predictions, such as those made by Bill Lucy and David Phillips in Tommorrow's Cities, Tomorrow's Suburbs. Taking a look at a number of indicators, they outlined the beginnings of a reversal of the 20th century story of urban decline. Instead they found evidence of city centers prospering and the aging suburbs around them falling into economic decline.

Take a look at these maps of changes in median income by census tracts between 2000 and 2005-2009, courtesy of the NY Times site. Orange is positive, blue is negative.

Charlotte, North Carolina

 Chicago, Illinois

 Cleveland, Ohio

 Columbus, Ohio

 Houston, Texas

 Indianapolis, Indiana

 Louisville, Kentucky

 Philadelphia, Pennsylvania

 Pittsburgh, Pennsylvania

 Washington DC

 Atlanta, Georgia

Atlanta offers a particularly striking pattern. During this interval, the median household income in the whole Atlanta metro area grew a reasonably healthy 12.4%. But looking just at urban Atlanta, we see a growth in median income of 44.5%. It turns out that Atlanta's wage growth is being driven almost entirely by wage growth in its core. The suburbs are still a tad bit wealthier in general, but that will probably not last more than a year or two longer.

Then see how this stacks up against the age of the housing stock in the core and the surrounding "suburbs."

Homes in urban Atlanta are, on average, much older than they are in the rest of the metro area. Despite the remarkable wage growth in the center of the metro, there still has been relatively little actual home construction for some reason. Less than 10% of all homes built since 2000 have been built in urban Atlanta (although it's worth noting that this share is up from the low of 5% in the sprawling 90s). Conventional wisdom says that wealthy people gravitate to newer homes, and the houses then trickle down to lower-income households as they are bought and sold over time. But wealthier people are moving to the core of Atlanta despite, or maybe because of, its older homes and neighborhoods.

One last important note: this census dataset doesn't do a very good job showing changes due to the housing market collapse, because the data is sampled from both before and after it happened. We'll have to wait a couple more years for Census data showing the new spatial patterns that emerge from the rubble.

Transit Oriented (affordable) Development

In case you missed it, the Dukakis Center for Urban and Regional Policy at Northeastern University dropped a bombshell of a report about Transit-Oriented Development (TOD) back in October. Key finding:

"Rising incomes in some gentrifying [Transit-Rich Neighborhoods] may be accompanied by an increase in wealthier households who are more likely to own and use private vehicles, and less likely to use transit for commuting, than lower-income households."

Ironically, they found that enhancing transit infrastructure can actually make ridership go down (and car ownership up) in the neighborhood it serves. That's a puzzling dilemma that deserves some attention.

TOD advocates have understood for a while that infrastructure and design need to be carefully coordinated to produce successful results. Just plop down a new station without changing any of the zoning codes in advance, and you're guaranteed to end up with a park and ride lot surrounded by much of the same 20th century stuff. There's transit, and there's development, but the orientation part is missing entirely.

Back in 2003, Patrick Seigman published a handy and oft-cited TOD checklist,"Is it Really TOD?"

"A true TOD will include most of the following:

• The transit-oriented development lies within a five-minute walk of the transit stop, or about a quarter-mile from stop to edge. For major stations offering access to frequent high-speed service this catchment area may be extended to the measure of a 10-minute walk.
• A balanced mix of uses generates 24-hour ridership. There are places to work, to live, to learn, to relax and to shop for daily needs.
• A place-based zoning code generates buildings that shape and define memorable streets, squares, and plazas, while allowing uses to change easily over time.
• The average block perimeter is limited to no more than 1,350 feet. This generates a fine-grained network of streets, dispersing traffic and allowing for the creation of quiet and intimate thoroughfares.
• Minimum parking requirements are abolished.
• Maximum parking requirements are instituted: For every 1,000 workers, no more than 500 spaces and as few as 10 spaces are provided.
• Parking costs are "unbundled," and full market rates are charged for all parking spaces. The exception may be validated parking for shoppers.
• Major stops provide BikeStations, offering free attended bicycle parking, repairs, and rentals. At minor stops, secure and fully enclosed bicycle parking is provided.
• Transit service is fast, frequent, reliable, and comfortable, with a headway of 15 minutes or less.
• Roadway space is allocated and traffic signals timed primarily for the convenience of walkers and cyclists.
• Automobile level-of-service standards are met through congestion pricing measures, or disregarded entirely.
• Traffic is calmed, with roads designed to limit speed to 30 mph on major streets and 20 mph on lesser streets."

But is there anything missing?

We're seeing that having a mix of incomes is not just a bonus policy goal, but something woven into the success of a TOD on it's own terms. On the one hand, attracting the professional class is realistically the only way to generate the capital needed to spur substantial redevelopment. But the service-sector workers are the ones who are more likely to forgo car ownership, use transit more frequently, and actually walk to work in that cool, mixed-use cafe. Both the urban design features the architects want and the return on investment the transit planners want depend on a healthy mix of incomes.

Many cities now seek to capture some of the value generated by their public infrastructure investment into land-banked supported affordable housing. Groups like Denver's Urban Land Conservancy carefully anticipate any market changes along transit corridors and grab some of the land before it becomes prohibitively expensive. Then innovative housing models, such as community land trusts, can be used to hold down the value of the land to a level affordable to low- to moderate-income households indefinitely. When these units are built they'll be doubly affordable, in both housing and transportation costs for the residents.

"Density, Diversity, and Design" is still the operative catchphrase, as long as by diversity we mean the people as well as the structures and uses.

Smart growth and fiscal responsibility

I noticed that Geoff Anderson, President and CEO of Smart Growth America, has come out in favor of the recommendations submitted this week by the National Commission on Fiscal Responsibility, at least the ones pertaining to tax reform.

"Unbeknownst to most, the federal government plays a massive role in the real estate market by subsidizing and enabling all kinds of development in our communities. With ballooning deficits, now seems like a good time to revisit these subsidies and make sure they are achieving a legitimate public purpose -and not, in the commission’s words, 'creating perverse incentives.'"

The smart growth movement has a long history of focusing on fiscal responsibility, dating back the the Costs of Sprawl published in 1974. This makes sense. Those of us who are too frugal to throw away the ketchup bottle before it's completely drained, cringe at the sight of underused parking lots being given over to weeds while far-off greener pastures are built on. It was all the more frustrating to watch this being done around the country with money that didn't actually exist. "Can we really afford this?" has been asked all along by John Norquist and James Howard Kunstler (albeit in very different ways!), and now finally this question is gaining some traction at the federal level.

The Home Mortgage Interest Deduction stands front and center in all of this. The deficit commission wants to limit the deduction to mortgages of $500,000 or less on primary residences. A healthy debate has been occurring among urbanist blogs about whether the HMID, in general, leads to a dispersal of housing. I'll dive in: I think no and maybe, depending on the region, but that there may be an important inter-regional impact to consider. My take on this is heavily influenced by Edward Glaeser and Joseph Gyourko's book Rethinking Federal Housing Policy (free pdf here).

In supply-constrained regions (like San Francisco), the extra money infused into the housing market by the HMID is swallowed up almost entirely into the prices of existing homes. There are few options for more development, so existing homeowners can simply raise their sale price to account for the buyer's willingness to spend more. This doesn't effect the built environment but it does mean housing affordability is compromised. In fact, the lower middle class takes a double-whammy with this. They pay taxes but don't make enough to use the deduction at all. Then they have to compete in a housing market inflated by the wealthier people who do benefit from the deduction. In these situations, the HMID may actually push people away from homeownership - the exact opposite of its stated purpose.

In elastic housing markets (like Houston or Detroit), the HMID probably does effect the built environment and drive down home prices to some degree. However, Glaeser and Gyourko's research indicates that the deduction is still not inducing much homeownership, because the subsidy is only available to wealthier households who are not usually the ones on the margin between renting and owning. They would buy anyway. Instead,

"A more important effect probably is on the quality of the home consumed, with people living in bigger and better homes than they would otherwise."

They question the wisdom of this tax incentive,

"In the old world of dumbbell apartments in dilapidated tenements, there may have been a case for government policies to improve quality and size. That case seems to much harder to make in today's world of suburban McMansions."

This is why I guess "maybe" for these regions. The quality improvement could mean either nicely-built craftsman bungalows or subdivisions of cavernous and disposable homes, but the HMID itself would not have much impact on the land costs - and that's what determines the spatial distribution of housing throughout the region.

What about the national scale? If the HMID pushes home prices higher in San Francisco and, at the same time, makes houses bigger for the same price in Phoenix, it's not hard to imagine some people who are considering a relocation to choose Phoenix partially on account of this effect. So the HMID may not make a region more sprawling than it would be without it, but it may help redistribute the national population away from places that are condensed to places that historically have been sprawling.

Bottom line: the HMID is essentially a one hundred billion dollar program for giving bigger homes to wealthier households in places that don't have much of an affordability problem anyway, all the while exacerbating the affordability in places where it already is a problem. It's not surprising that a group like Smart Growth America may question whether this is the best use of taxpayers' money in an era of overwhelming deficits.

UPDATE:  Here's a recently published study on the Home Mortgage Interest Deduction that puts some empirical meat on the bones I've described here. The Modeled Behavior blog summarizes the results:

"Using national data from 1984 to 2007 they found that the MID did not increase overall homeownership. In areas with light land use regulation they found that homeownership among higher income families was increased, and in tightly regulated housing markets homeownership was decreased for all income groups except the lowest. The effects, both positive and negative, generally range from 3% to 5%. Regardless of the regulatory environment, homeownership among the lowest income group was not affected at all by the MID.

The authors estimate that it each additional homeowner created by the mortgage interest deduction costs the government $53,590, a number they rightly call “staggering”.

An important implication of the findings is that in urban areas, where land use regulations are typically more restrictive, homeownership is likely to be negatively impacted."