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How Green are Cities?
Ed Glaeser writes:
Manhattan, not suburbia, is the real friend of the environment. Those alleged nature lovers who live on multiacre estates surrounded by trees and lawn consume vast amounts of space and energy. If the environmental footprint of the average suburban home is a size 15 hiking boot, the environmental footprint of a New York apartment is a stiletto-heeled Jimmy Choo. Eight million New Yorkers use only 301 square miles, which comes to less than one-fortieth of an acre a person. Even supposedly green Portland, Ore., is using up more than six times as much land a person than New York.
New York's biggest environmental contribution lies in the fact that less than one-third of New Yorkers drive to work. Nationwide, more than seven out of eight commuters drive.
I get the point but I don't quite buy this. Manhattan sells services, most notably finance and entertainment, to the rest of America, and in turns draws upon industrial outputs, which of course include steel and glass. It is also no accident that Gary, Indiana is near Chicago and those rather aesthetically thrilling factories off the New Jersey Turnpike are right outside New York City. Try the other boroughs as well, they don't call Staten Island a big garbage dump for nothing. Praising Manhattan is a bit like looking only at the roof of a car and concluding it doesn't burn much gas. Manhattan supports its density only by being surrounded by a broader load of crud.
Perhaps a better question concerns the margin. If we tax Peoria and subsidize Manhattan an extra bit, and induce some migration, does the total environment footprint of mankind go up or down? For instance building up rather than out saves space but it also costs more construction energy and attracts more commuters and leads to more surrounding crud.
If you think the big problem is humans grabbing more and more space, you might prefer to tax suburbs and subsidize cities. If you think the big problem is humans using more and more energy, the opposite conclusion might follow. Suburbs are bad for burning gas, but they are an especially efficient place to work, buy things, and raise children.
A subsidy to 5th Avenue is also a subsidy to Port Newark. Think of Manhattan as a place which outsources its pollution, simply because land there is so valuable.
Posted by Tyler Cowen on February 1, 2007 at 10:03 PM in Economics | Permalink
Comments
Hi Tyler,
Glaeser and I have written on the benefits of sprawl. A free copy of our Handbook Chapter is available here:
http://www.econ.brown.edu/faculty/henderson/handbook.html
When a yuppie lives and works in Manhattan, he lives a more compact "new urbanist" life that requires less driving and energy consumption than
if the same guy suburbanized. The definition of suburbia is having more private space. This offers private environmental benefits (your own lawn) but
imposes social costs.
You are right that rusting urban industrial America is gross but declining transportation costs have allowed for a separation between
consumption and production. Urbanites can purchase manufactured products that were made in rural areas using new manufacturing technology. This is the
Coase theorem at work! I have written about domestic pollution havens but the public health costs are low when a new clean factory produces
in a low density community and then ships final output to big cities.
You are right that the Staten Islands and Gary Indianas of the world need a makeover. This is why Glaeser's work documenting "Consumer City" is such an important idea.
Durable capital in these cities must be ripped down and brownfields need to be transformed into greenfields and then hold an auction to
allocate the land to the highest bidder.
As you know, I discuss all of these issues in my Green Cities book.
Posted by: Matthew Kahn at Feb 1, 2007 10:33:49 PM
>If we tax Peoria and subsidize Manhattan an extra bit,
>and induce some migration
Subsidize Manhattan an extra bit? Manhattan is subsidizing the rest of the country, not vice versa.
Posted by: richard at Feb 1, 2007 10:47:57 PM
I don't think your objection quite addresses the point. It seems to me that Glaeser is claiming that it is the residential pattern of Manhattan, not its business activity, that is easier on the environment than suburbia.
Surely it is unarguable that a person living in a relatively small apartment in a high-rise, or even a 3-4 story building, is less of an environmental burden that the suburbanite with a lawn, etc. This is even more the case when many of these people ride subways to work rather than driving.
It's probably true that building "up rather than out" uses more energy, per square foot, in the construction process, but I don't see why that's the end of the calculation of comaparative energy use. Small uses less than big.
Posted by: Bernard Yomtov at Feb 1, 2007 11:05:09 PM
Tyler, why are you thinking only of the up-front costs of the construction process? Surely you understand that the lifetime energy costs of a large residential building with many housing units are much lower than the energy costs in an equivalent number of housing units in smaller buildings in the suburbs? Add to that the energy costs of transportation for those commuting from suburbs and the difference is enormous.
Posted by: Joey at Feb 1, 2007 11:22:58 PM
Here's my own thought experiment: if we applied a Pigovian tax on energy pollution and -- what looks to be Glaeser's focus -- on land (say an extra $10 per acre per year), on whom would these taxes ultimately be incident? We (I live in Brooklyn) eat food grown on farms, and thus use farmland, but I have little doubt we would pay less in this land tax than suburbanites or others would. Energy used to heat/cool our homes (tiny little apartments) and for commuting are also, I expect, less than for the average person in Iowa (where I grew up).
I don't expect that most people who read this blog think that they can blame the power company -- or the town in which it sites its plants -- for the pollution produced when they consume electricity, or that they aren't responsible for the space they use in the landfill. It's still less than it would be if we lived a more spread-out existence.
Posted by: dWj at Feb 1, 2007 11:24:13 PM
A paradox, then: highly urban areas are more efficient places to live; yet they are also more expensive areas to live. Why the long-lasting disequilibrium? What is the urbanite paying for, if they consume less?
(Any scarcity-based response should also deal with the notion that the supply of urban real estate is not, in the long run, inelastic. Manhattan has not always been there.)
Posted by: Cyrus at Feb 1, 2007 11:30:55 PM
"Suburbs are bad for burning gas, but they are an especially efficient place to work, buy things, and raise children. "
Tyler - I don't quite follow your reasoning. When I lived in a city, it was easy for me to get to a store. Now that I live in the burbs I have further to travel, and I do so in a single person vehicle. How is this more efficient?
Posted by: Anonymouse at Feb 1, 2007 11:49:44 PM
Cyrus:
political culture which fetishises 'family home', car culture, and over investment in these; the richer people living in suburban areas pulling more money into generalized subsidies which poorer people can then take advantage of, etc
Posted by: yoyo at Feb 2, 2007 12:08:26 AM
I have a really good idea. New York should keep all it garbage, turn it into compost and/or mulch and raise all its comestibles on the rooftops and other open areas. That way they won't waste all that energy bringing in and hauling out stuff from and to other places. Maybe put a big plastic dome over the city and make it Spaceship New York.
Posted by: JorgXMcKie at Feb 2, 2007 12:14:58 AM
An aside: it's irritating that Pigovian social engineering seems to be all the rage among economists these days. Many one-time libertarians have morphed into policy-wonky kids in the candy store with all their wonderful ideas about how they're going to use "externality capture" to hammer society into a form more suited to their prejudices. Maybe it'll even bring about the New Soviet Man!
Posted by: Foobarista at Feb 2, 2007 12:37:35 AM
Cyrus: If you take a course in microeconomic theory, your paradox will go away immediately. Under the standard economic conception of "efficiency," situations in which externalities are not internalized due to high negotiating costs, weak contract law, and government inaction are inefficent. Consider a parallel question:
"A paradox, then: candy factories that pay Pigovian taxes on pollution produce candy more efficiently; yet they also produce candy more expensively. Why the long-lasting disequilibrium?"
It is possible that Tyler is right, and city life is less efficient; maybe Glaeser is right, and it's more efficient. But there is certainly no paradox.
Posted by: oii at Feb 2, 2007 12:58:08 AM
A related thought came to me when I read some report about how China's economy would stop growing at some point because its energy usage per GDP was much higher than that of the US. But, it is the higher energy usage per GDP of China that enables the lower one of the US, because the US needs the things China uses a lot of energy making and returns debt and less energy intensive things.
Posted by: bhauth at Feb 2, 2007 4:30:42 AM
dWj:
A tax on land would simply incide on *landowners* with no excess burden on the economy (provided that it was less than the total land rent). The pattern of land *use* is irrelevant - in fact, land taxes typically spur efficiency by discouraging land speculation and increasing allocative liquidity. This is one of the most firmly established principles of economics.
Posted by: guest at Feb 2, 2007 5:04:20 AM
The China point is a good one: the US and other countries that trade with China are offshoring their pollution and CO2 emissions to China.
Posted by: Foobarista at Feb 2, 2007 5:27:53 AM
Trying to put together the many good points made so far, I think the relevant question is: In a global economy (I live in Chile), why may the expected environmental cost of a new born depend on where he/she is born? There may be two reasons for significant cost differentials. One is wealth: the wealthier the new born is expected to be, the higher the environmental cost. Wealthy people are likely to live in places where the environmental cost of providing local services to them is the highest (from Tyler's comments, I assume that the papers by Glaeser and others don't take into account the environmental cost of providing these services to Manhattan residents). The other is the large distortions in current location patterns due to government intervention but also to "spontaneous" segmentation. Albeit difficult to assess, the distortions may be more important than wealth.
Posted by: Edgardo at Feb 2, 2007 5:29:21 AM
All these arguments seem superficial to me. No one has talked much about water, sewage, and electricity/natural gas. In most systems the desire is for the most decentrallized that still spans the problem.
Coastal cities could be replaced in a business infrastructure with better telecommunications, super-super-ships that never enter a port and hovercraft that could land large cargoes at most shore points.
The only function that can't be replaced is as a vacation destination.
Posted by: huggy at Feb 2, 2007 7:17:21 AM
What Bernard Yomtov said. I don't see how it can be denied that residential living patterns among lawyers like myself who live in New York City are much more energy-efficient than they are among my many colleagues who live in Chappaqua. It has nothing to do with our line of work (we're all lawyers), but our mode of life. (Just as a tiny example, the heat from my apartment goes to my upstairs neighbor, the heat from a house in Chappaqua is dissipated through the roof.)
I don't think the non-commuting utopia envisioned by huggy is viable. Millions of years of evolution as a highly social species have made us very good at assessing people whom we meed face to face, and much less good at assessing people with whom we communicate by email. The bonds of trust and understanding, which are essential to business commerce, will always require face to face contact.
Posted by: y81 at Feb 2, 2007 9:15:36 AM
You're all just considering the benefits from the living patterns, and not the environmental costs from the accompanying economic activities needed to sustain population density.
Posted by: Tyler Cowen at Feb 2, 2007 9:25:43 AM
The New Yorker had an article about this several years ago. See here.
Disclaimer: the author is a family friend.
Posted by: Dave at Feb 2, 2007 9:27:19 AM
I'm going to point you to a (rather long) essay by Paul Graham, called Why Nerds are Unpopular.
http://www.paulgraham.com/nerds.html
One of his points is that the "teen angst" that we have in the "modern world" is a side effect of suburbia. Young adults, in previous centuries, worked, or at the minimum had something useful to do. Today, they're locked up in an environment that degenerates into something closer to Lord of the Flies.
While some folks complain that Paul's representation of Jr High and High schools doesn't represent their experience, I've also met folks for whom it is an accurate depiction of their teen years.
If you read Jane Jacobs, cities have a reason to exist, and when you have an import replacing district, it will always grow into a city.
The suburbs were made possible by cheap gasolene, and when the age of cheap gas is over, the suburbs will vanish. Looking for alternative energy or alternatives to the car culture poop out because those alternatives can't be made to keep the suburbs going.
Posted by: Peter at Feb 2, 2007 9:50:58 AM
Clearly the difference in domestic land use isn't the whole story but cities are more efficient than suberbs in the resources in per capita. Sure every new yorker needs a certain amount of land to supply them with food. A certain amount of land to dispose of their waste. But people in the suburbs need more of both of these. It makes no sense to me to suggest that people living in smaller spaces who walk or take public transportation to go to their jobs and to do their errands are somehow less efficient than those in the suburbs because they need to do the same things that people in the suburbs need to do too. The argument is like saying that 15 is less than 1 when you add 20 to both sides.
Posted by: Michael Foody at Feb 2, 2007 11:00:37 AM
I could be missing something here, but isn't this debate resolved by calculating the full energy consumption of the average urbanite vs. the average suburbanite--that is, not just whether they drive and how far and how much it costs to build their home, but how much energy and what kind is used to provide their power, heat and AC and to produce and transport their food and clothing etc. I'm aware that this would be a knotty calculation, but I suspect someone has done it.
But I agree with Tyler's underlying point that there's a lot of anti-suburban posturing and environmental self-righteousness among urbanites (and I'm one and probably often guilty too). I suspect the 'burbs beat the cities on some green indicators and fall short on others.
Posted by: Tim Gray at Feb 2, 2007 11:05:19 AM
You're all just considering the benefits from the living patterns, and not the environmental costs from the accompanying economic activities needed to sustain population density.
Are you referring to the economic activities of Manhattanites, like finance and entertainment services, or the activity needed to support residents, like utilities, garbage disposal, etc?
Would either of these make less of an environmental impact if the residents of Manhattan were all spread out in suburbs? Seems unlikely to me.
Posted by: Bernard Yomtov at Feb 2, 2007 11:11:02 AM
Tyler,
I think whether we should prefer density would depend. Density might easily win on both energy use and land use counts if the population stabilizes or if urban density contributes to lower birth rates. That should close the gap between energy use in cities and in suburbs because the buildings are sunk energy costs; provided the replacement rate for high density residential and commercial development is low enough, it should produce savings in land use and energy long term.
Posted by: Steven Schreiber at Feb 2, 2007 11:45:37 AM
I don't follow Tyler's point. In what way is more energy consumption required to sustain my urban lifestyle than what is required to sustain my colleagues in Chappaqua? We both shop at grocery stores that receive their supplies by truck (only the last mile of the delivery paths is different). They shop at shopping malls and I shop at department stores which, again, lie at the end of very similar delivery paths. Can someone give an example of an energy-intensive activity that is required to indirectlys support my lifestle and not that of my suburban commuter colleague?
Posted by: y81 at Feb 2, 2007 1:34:05 PM
