Monday, 3 July 2006

'Sustainable' cities are unaffordable cities

Here's something to ponder. Below are two charts comparing certain aspects of several cities.

The first is a chart prepared to compare the 'sustainability' in 2005 of twenty different US cities -- in other words, the level of wetness adopted by city planners, and the extent to which land-use restrictions are imposed and property rights ignored. (The methodology is outlined here. The rankings for 2006 are here.)

The second chart (below) compares the affordability of several of the world's cities, with 'severely unaffordable' cities at the top and affordable cities at the bottom. (Affordability is given as a multiplier of that city's average income.)

Just by comparing the two charts you'll see an obvious trend: cities ranking highly in one chart generally rank rather highly in the other chart as well. In other words, cities that are highly 'sustainable' also tend to be highly unaffordable -- no surprise when 'sustainability' usually takes the form of restricting the supply of housing in some way. Examining the figures for the top ten 'sustainable' cities only confirms this:

1. Portland (29th Most Unaffordable US City, with a Multiplier of 4.2 times the average income, making it seriously unaffordable.)
2. San Francisco (5th Most Unaffordable US City, with a Multiplier of 9.3 times the average income, making it severely unaffordable!)
3. Seattle (18th, 5.3 - severely unaffordable)
4. Chicago (23rd, 4.9 - seriously unaffordable)
5. Oakland (not measured)
6. New York City (7th, 7.9 - severely unaffordable)
7. Boston (15th, 6.1, severely unaffordable)
8. Philadelpia ( 32nd, 3.9, moderately unaffordable)
9. Denver ( 19th, 4.0, moderately unaffordable)
10. Minneapolis (30th, 3.5, moderately unaffordable)

So many of the the 'most sustainable' cities are also amongst the most unaffordable. Being dripping wet costs money, and it seems that first-home buyers are the ones forced to meet that cost the most. Turns out too that the 'least sustainable' cities by the wetness standard generally rank amongst the less severely unaffordable places in which to buy a home:

40. Tulsa (8th most affordable city in the US, 2.6 - affordable)
41. Arlington (not measured)
42. Nashville (26th most affordable, 3.3 - moderately unaffordable)
43. Detroit (24th most affordable, 3.1 - moderately unaffordable)
44. Memphis (26th, 3.2 - moderately unaffordable)
45. Indianapolis (4th most affordable, 2.4 - affordable)
46. Fort Worth (not measured)
47. Mesa (not measured)
48. Virginia Beach (xxth, 4.0 - moderately unaffordable)
49. Oklahoma City (10th most affordable, 2.7 - affordable)
50. Columbus (20th most affordable, 2.9 - affordable)

Only Kansas City (18th) and the Lone Star State's Austin (14th) register both in the top-twenty dripping wetUS cities and the list of US cities that are affordable. Clearly there are other factors at play as well, but denying there is some correlation between restricting the supply of land and of development, and the resulting cost of supplying land and housing is like trying to deny the passing of the seasons.

You can argue all you like about the benefits of 'sustainability,' but the extent that 'sustainability' is imposed on cities by restricting the supply of land and housing appears to be the extent to which that city is made unaffordable to first-home buyers.

It would be interesting to try such a correlation across New Zealand's cities, except for two things: the first is that all New Zealand cities have essentially the same restrictive land-use policies so there's little variability to measure; the second is that, as a consequence of those restrictive land-use policies, all major New Zealand cities rank in the 'severely unaffordable' category.

LINKS: 2006 SustainLane US City rankings - SustainLane
2nd annual international housing affordability survey, 2006 - report at
'NZ housing affordability in crisis' says report - Not PC (Jan, 2006)

TAGS: Urban_Design, RMA


  1. I wonder to what extent these big, rich and gentrified cities are sustainable only because a mass of other cities exist to soak up the unsustainable functions and house the middle and lower classes. In other words, can all cities be made sustainable in the US or would it all collapse under its own weight?

  2. What cities have not sustained (failed) in the US, for reasons other than the loss of a major employer?

  3. "You can argue all you like about the benefits of 'sustainability'...

    Sounds like an own goal: sustainability is not achievable in an unregulated environment. It costs more to live somewhere nicer... sorry, am I missing something?

    PC, surely people can choose to spend more to live somewhere more sustainable, or spend less and live elsewhere.. or would it be preferable to you if all places were similaryly deregulated and similairly non-sustainable?

    Finally, inherent in the argument for sustainability is the long term costs/saving associated with, you guessed it, sustainable living. 'Affordability' is not the only 'cost'.

  4. "surely people can choose to spend more to live somewhere more sustainable, or spend less and live elsewhere"

    When the regulation prices people out of owning their own homes.

    PC isn't asking for no regulation, simply property rights. If you don't interfere with someone else's property, why does it matter what you do, or what you consume?

  5. Because what you do or consume invariably does interfere with other peoples property.

    Let's be real: regulation clearly does not price people out of owning their own home. It does prevent some people owning some homes, as is already the case.

    To take a Libertarian line, if I want to live somewhere with a policy of sustainability and have the money to afford it, what right do you have to say that I should not live in such a place?

    I am not saying that everything needs to be regulated, but you're implying there is no worth in sustainable living. If the benefits of sustainability come at the cost associated with regulation then so what? There is a cost associated with everything we consume or do. What was the point of the original post?

  6. PC, you state there is a definite correlation, but throwing the numbers into a spreadsheet reveals a correlation of -0.35, p = 0.14.

    English translation: there IS a correlation, but it isn't huge and it is NON-SIGNIFICANT. This is mostly due to the number of cities involved (we only have data for 19 cities) - with 30 or 50 cities I'd bet money that the correlation would be significant.

    So what's the point of my post? If you want to make a strong statement like "deny the passing of seasons" the you need to have the objective facts to back up your opinions. You need a little more data before you make such a bold claim ...

  7. "Because what you do or consume invariably does interfere with other peoples property."

    How does making a phone call do that, for example? My property using the phone company's property with its permission.

    If regulation puts the price up of some homes by definition it prices all homes higher, restricting supply pushes prices up, you can't have it both ways.

    I wouldn't stop you living somewhere sustainable - whatever that means (and it is never defined well), but you cannot force regulations on others. If you can get a community together of liked minded people who all agree, then fine - but don't use government to make others do it.

  8. By almost every definition of 'sustainability' it means in some fashion restricting the supply of land for housing. As polemic concedes in his very question: "sustainability is not achievable in an unregulated environment."

    As regulation pushes up the costs of supply, so the affordability of housing becomes a problem -- and as your city becomes more unaffordable, they also become in fact truly unsustainable.

    The point here is that the conditions for 'sustainability' laid down by organisations such as Sustain Lane don't necessarily make a city any better in which to live, they just power politically correct planners to meddle with people's property.

    Luke, I'm not sure which numbers you thre where, but there are more than nineteen cities in common between the two lists, so you've definitely missed a few in your working.

    And if you're saying that there is no connection between there being NO affordable cities in the list of top ten sustainable cities, and NO severely or seriously unaffordable cities in the bottom ten, then I suggest you check your maths.

  9. I used the affordability figures in this pdf:
    I got the sustainability figures straight from the graph:

    There are 25 cities on the graph, but six of those don't have affordability figures (Berkeley, Santa Monica, Oakland, Madison, Scottsdale and Chattanooga) leaving me with 19 pairs to analyse.

    I am not denying there is a correlation, just pointing out that to be scientifically standard-of-proof SURE about it, we'll need to have some more figures, not just compare the top ten and bottom ten. That's lazy fuzzy socialist-style thinking, Cresswell ... shouldn't we assess reality objectively.

  10. Luke, there are fifty cities in the SustainLane 2006 report, most of which correlate with the 66 cities in the Demographia Housing Affordabily survey.

    Without your working it still seems rather spurious to suggest there's no real correlation between restricting supply (as 'sustainability' does) and the cost of that supply.

    In any case, there are two different qualities of figures here. The affordability figures are real world figures measuring prices against income. The 'sustainability' figures on the other hand are a subjective assessment of a number of factors made by the apostles of meddling wetness at SustainLane.

  11. Ok I redid the correlation with more data; there is a correlation of 0.42, p - 0.005 (significant).
    This is a VERY GOOD correlation.

    In addition, regression tests demonstrate that the correlation is 'caused' by the influence of sustainability scores on affordability (regression: 2.28), not vice versa (regression: 0.07), further backing up PC's claims that policies of sustainablity cause higher house prices.

    Well done PC, you've been fully vindicated. :-) Maybe we should try and get this published somewhere ... a useful footnote for a free rad article? I dunno, perhaps it is too boring .. I've been in academia for too long. :-)

  12. One assumes the affordability is based in current economic procedures. The un-forseen 9/11 & war on Iraq is actually drawing American tax dollars from other tasks, such as post-Katrina recovery or national healthcare or the deficit or the unbalanced budget etc. etc. The cost of that is surely not reflected in locality-based affordability is it?

    And global warming does exist, regardless of why-who caused it, and even if it doesn't ruin major cities & port facilities in America it will dramatically distort global money flows & where-how big debt is (how many hundred million Bangladeshis will have to move entire cities up-inland? How soon?).

    Where are those costs reflected in conventional affordability indices? How is the cost of increasingly extinguished species & decimated ecosystems-habitats reflected in 'affordability'? If I can no longer buy insulin, or decent coffee, or lumber, or soybeans, at an affordable price from peak-oiled and climate-challenged world markets then don't I prefer a sustainable city to one still living in the previous now broken economy? In a sustainable city where through whatever mechanisms I can acquire affordable, healthfully produced foods I will be living. On the Jersey shore or the Gulf Coast, in many as yet unknown places as drought or more frequent/more severe storms devastate crops & travel & power systems, I will be willing to pay whatever it costs for clean water, fuels, foods as times get harder. And I will be glad if I chose to foster those industries now.

    And what if climate-change data are wrong, we are mistaken or someone invents free teleportation such that the world is spared such hardships? And what if I've chosen to pursue sustainability (efficiency & conservation, clean water & air, short job commutes, healthy local food systems, preventive healthcare, etc.)?

    How have I lost choosing this better life path, regardless of the difficult-to-predict future?

    Let's get statisticians' heads out of the books and look at what kind of world we want to live in. Let's work together to build THAT.

    = from Philly: affordable AND sustainable, and getting better at both

  13. This is a moot comparison. Does Portland produce all its own food and electricity?


    Then why are you calling this "sustainable"?