Thoughts for January 1, 2023
Happy New Year. Only two topics this week: demand-side solutions and the 15 Minute City (again).
Demand-Side Solutions
There was a paper from last year two years ago on demand-side solutions (that is, reducing demand) to climate change. It is a survey paper, covering a range of areas including urban design, diet, material usage, and others.
The title of the paper is “Demand-side solutions to climate change mitigation consistent with high levels of well-being”, and as it suggests, a “solution” is a policy that enhances well-being as they measure it. How do they measure it? I find their methodology opaque, but they consider 18 aspects of well-being: food, water, air, health, sanitation, energy, shelter, mobility, education, communication, social protection, participation, personal security, social cohesion, political stability, economic stability, material provision, and a category for “supply side/incumbents”, who presumably prevent these solutions from becoming reality. The impact of each solution on each measure of well-being is based on expert judgment.
The paper is useful as a collection of references on the range of topics, but not for much else. But I think it is worth dwelling on some of the problems because they represent the approach of large shares of the environmental movement in thinking about these issues.
First off, any of discussion of well-being, in lieu of a rigorous economic analysis, immediately triggers suspicion. Where did the 18 metrics of well-being come from? I don’t see where personal freedom is reflected in these metrics, though the metrics are vague enough that maybe it’s there. I don’t really see any explanation of any of them. Who are the experts making these evaluation, how representative are they of the range of academic thought, and how reliable are their judgments? I don’t have clear answers to any of these.
There are nuggets of wisdom like these:
Avoid: flights
Aviation is of low economic value and demand is highly sensitive to prices. A carbon price of aviation fuel of $400/tCO2 would halve demand for aviation in 2050
That’s a dismissive judgment for sure. And why is a $400/ton carbon price suggested? A value of $400/ton is well above almost all mainstream estimates of the social cost of carbon, as well as the cost of mitigation measure that would cover most emissions.
And this:
Shared housing (e.g. shared kitchens), improves communication between neighbours, or coinhabitants, though design issues, and the predisposition of inhabitants are important (Baum, 1986). People with dementia benefit from shared living arrangements. Shared urban spaces enhance virtual and physical communication among urban communities. Appliances sharing system build on social group communication, both requiring this and fostering it. Adaptative reuse of buildings enhances social networks and maintains native ways of life.
Okay ….
Obviously, when we talk about as broad a concept as, say, compact cities, there are a huge number of relevant considerations. There is no way to enumerate and compare the considerations, even if one tries to do so in a fair-minded way, which this paper does not appear to have done. But there is, nonetheless, a way to navigate the tradeoffs. It’s called economics. The authors would, I presume, assert a very big gap between the economics of urban development, as reflected through real-life financial analysis, and how they say cities should be built with proper consideration of environmental concerns and needs for well-being. That gap is handwaved as follows.
Third, income and expenditures reflect only a part of well-being, and monetary cost evaluations, even if starting from a broader framework, often ignore encompassing views on multiple dimensions of well-being. This critique is not new and, on the aggregate scale, there is agreement among economists and philosophers, and in other disciplines, that metrics such as gross domestic product (GDP) insufficiently reflect well-being, and that these must be complemented by more encompassing metrics.
This is an example of what I described last week as the SimCity approach to policy-making: grand visions of how society ought to operate that are not based on a serious consideration of human needs. The discussion of well-being has the character of an ex post facto justification for preferred policies.
This is not to say that all policies in the paper are bad. Some of them seem good, such as less cautious expiration date labeling, and many I don’t understand well enough to make a judgment. But if they are good policies, this paper does not make the case for them.
15 Minute City
Yeah, this topic again. I’m bringing it back up because there was recently an interesting paper on the subject.
To review, the 15 minute city is a concept in urban planning that holds that all of a person’s common needs should be fulfillable within a 15 minute walk, thereby reducing the need for a personal automobile and the space and other negative effects of the vehicle. Among other occasions, I wrote about the subject here.
A few points raised in the paper:
12% of trips taken in the U.S. are to destinations reachable in a 15 minute walk. That percentage is higher in the Northeast than in other parts of the country.
More trips in a 15 minute walk range is associated with higher population density and less car ownership. No surprise there.
“A one percentile increase in access is associated with a .8 percentage point increase in the share of trips that are within 15 minutes walking distance. This coefficient is not particularly sensitive to other controls, including population density, income and share of the population in the block group that owns a car. This correlation does not imply that encouraging more mixed-use development within residential areas will reduce average trip times, but it is certainly compatible with that hypothesis.” Again, that’s what we would expect, and it shows that at least on this level, the 15 minute city methodology holds.
But there is a possible confounding factor of selection: people who prefer walkability might locate to more walkable neighborhoods, as opposed to more walkable neighborhoods causing people to walk more. The same may be true for businesses: those more geared toward pedestrian traffic may choose to locate in walkable neighborhoods.
Zoning is a major factor that interferes with high walkability.
“We find that 15-minute usage is strongly positively correlated with experienced segregation for the poor and negatively correlated with experienced segregation for the rich. We do the same thing looking at 15-minute access and find analogous results. These results support the view that, while improving access to amenities reduces trip lengths, it also poses risks of exacerbating the social isolation of marginalized communities.”
Ed Glaeser, one of the co-authors of this paper, made the last point in a blog post as well.
I wonder if there is a contradiction in the last point, though. Consider that there is a well-observed correlation between fires in a city and the presence of fire trucks. It would not follow that getting rid of the fire department would get rid of fires. Likewise, if walkable neighborhoods attract more affluent residents because they are preferred, it would not follow that improving walkability would lead to more segregation overall. However, I am more persuaded by the argument that restricting transportation access—a key point of making the 15 minute city work—would in fact create ghettos and worsen segregation.