41 Comments

These “X interesting things” posts are turning out to be as good and satisfying as Noah’s single-topic pieces.

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author

Glad you like them!

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Aug 9, 2023Liked by Noah Smith

I might be misunderstanding, but I’m struggling to understand how that quote from the abstract supports your point that deregulating ADUs “helped make housing more affordable.” The very next line of the abstract is “However, a linear panel model shows that ADUs are insufficient to decrease rent.”

Moreover, the author explicitly states later in the article: “I conclude that ADUs deregulation is not driving any meaningful reduction in rent prices.

This provides some evidence that reliance on single-family parcels is not an effective strategy to reduce rents.”

It seems like the evidence is showing deregulation increases supply specifically, but that hasn’t necessarily translated into statistically significant reductions in rental prices. Can you clarify this?

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You're right. I meant to type "make housing more abundant", and carelessly mis-typed. The laws increased construction, but so far the difference in rent due to the increased supply is only maybe 3%. Not nothing, but not a significant change in affordability!

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Aug 9, 2023Liked by Noah Smith

Oh great, thank you! I was trying to parse the methods around the ‘feasible effect’ and thought I might be getting confused! Very interesting research, so thanks for including it!!

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author

Thanks for catching that!

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Well, do you mean "more affordable in absolute terms", or "more affordable relative to what it otherwise would've cost"?

The evidence that adding supply "bends the cost curve" is pretty robust. We're just still not adding supply in super-star metros as fast as we're adding jobs. Plus there's been general inflation. So we're not seeing prices come down in absolute terms.

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I think it’s very clear that I mean what I said in my comment: the author of the cited study said “However, a linear panel model shows that ADUs are insufficient to decrease rent” and “I conclude that ADUs deregulation is not driving any meaningful reduction in rent prices.

This provides some evidence that reliance on single-family parcels is not an effective strategy to reduce rents.”

The robustness of the overall evidence around bending the cost curve is not really relevant to what I wrote.

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Aug 10, 2023·edited Aug 10, 2023

I don't think it's obvious whether the quoted text means absolute or relative either.

But FWIW, Minneapolis is seeing at least some people report absolute reductions in rent, because they're doing it right.

https://twitter.com/cayimby/status/1689327748236648448

https://twitter.com/aceckhouse/status/1689433727158673408

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The paper is using a DiD model, so it’s effectively saying ‘ADU deregulation had no statistically significant impact on rental prices in the treatment group of neighbourhoods compared to those in the control group.’

Effectively, it compared neighbourhoods that would have seen the greatest capacity increase from ADU deregulation and compared (log) rents to those in neighbourhoods that would not have seen less increase in capacity and concluded that ADU deregulation did not make a statistically significant impact on rental prices. So to answer your question, it is looking at relative changes both spatially and temporally.

I can’t access the article you linked, but I’d like to emphasise that my comments are very specifically about the effects of ADU deregulation as discussed in the linked paper not the broader question of whether increased supply reduces costs (be it absolute OR relative)

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Aug 9, 2023Liked by Noah Smith

This one feels like a mega thread. So much going on.

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With YIMBYs winning intellectually, can we also do away with the term "affordable housing"? More housing IS affordable housing. We should be building where it is most economically efficient to do so, not subsidizing the bottom of the housing market. The end result will be the same: More supply for low and middle income families.

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We do probably want to subsidize the very bottom though. Even market urbanism poster child Tokyo has more public housing than US cities, including subsidized public housing (toei/kuei/shiei not UR).

At some sufficiently low level of income, a household won't be able to afford even the cheapest options, especially families.

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Aug 10, 2023·edited Aug 13, 2023

Agree, but in this case I believe subsidizing the person is a better approach than coercing builders to deed more affordable units. Thats quite a long conversation all in itself.

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I think room temperature superconductors are a case of the perfect being an enemy of the good. Even superconductors that could be cooled by liquid nitrogen would be a huge breakthrough. We actually already have superconductors that function at those temperatures, but the problem is most of them are ceramics that are hard to manufacture at scale, and are too brittle for medical/scientific/industrial use.

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> So not only is it not clear whether Americans suddenly care much more about mortgage rates in a post-pandemic world, it’s not clear why they would. It’s still a mystery.

Uhhh, maybe the housing crisis? When houses are already unaffordable to most families, interest rates suddenly take on a huge relevance.

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> When houses are already unaffordable to most families

65.8% of Americans own a home as of 2022.

How can housing be "unaffordable to most families" when most families own a home?

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Because most families didn’t purchase those homes in the last year.

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Along the lines of https://www.slowboring.com/p/why-are-young-liberals-so-depressed, I'm inclined to think the difference between predicted sentiment and actual sentiment (to the extent it really exists) has more to do with political polarization, misinformation and catastrophization than it does perceptions pertaining to the actual economic indicators themselves.

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Something I think missing in this overall analysis is that the Michigan consumer sentiment survey has been polarized in recent years across party lines https://www.nytimes.com/2017/04/08/business/economy/the-picture-of-our-economy-looks-a-lot-like-a-rorschach-test.html

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In re superconductivity, AMSC has made significant advances. As a sideline, it’s created a technology that makes U.S. Navy ships invisible. As for cheap rocket launches, RKLB dominates the small-rocket sector and can launch a payload into space in 24 hours or less after receiving the payload. They offer to park a rocket for a client, launch approval/paperwork, and logistics from New Zealand is quick because of the light density of commercial air traffic. FYI: The CEO rocket scientist, Peter Beck, never spent a day in college. A pure-play public rocket/satellite/space vehicle design and construction company, it’s the only competitor Elon Musk follows on X.

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Regarding room temperature superconductors, it looks like the US Navy was first.

https://patents.google.com/patent/US20190058105A1/en

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Aug 9, 2023·edited Aug 9, 2023

Re: the sulfur rules -- ocean acidification is one of the places where there _may_ be a truly scary/catastrophic tipping point if you do it too fast. If you make it so a diverse array of diatoms and other phytoplankton can't assemble their shells anymore, you could on a very short time scale lose something like 10-20% of the world's entire capacity to cycle carbon back into O2. Which would only steepen the warming curve. It's maybe theoretically possible to recover from this, if you can move to having a huge investment in actively removing carbon, but if we end up in resource wars and large-scale tech interventions like that get to be impossible, then you've put the world on track for a truly horrendous mass extinction event.

I think _most_ global warming scare scenarios that imagine humanity going extinct, or even having a major die-back, are pretty absurd. For most of the range of outcomes, life will be worse than it should've been but will go on. The version driven ocean acidification is one of the few that's actually plausible. Probably not super likely, but not impossible.

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(Apologies for the very long comment. I wanted to take advantage of the recent interest in materials to explain a little bit about the research in the field, and to give a brief summary of a few popular materials that have been the subject of a lot of recent research. The last part has some information on specific types of materials if you want to skip to that.)

With the recent interest in new materials from a broader segment of the public, I thought it might interest people to summarize some of the different research directions people have in this field. First, it’s a very broad field with people from a range of different backgrounds contributing. People with a background in physics, materials science, chemistry, chemical engineering, and even computer science and electrical engineering participate in research related to materials. Depending on the specific focus and the background of the person doing the research it could be labelled as condensed matter physics, solid state physics, materials science, inorganic chemistry, or solid state chemistry. People with different backgrounds might tend to cluster in different sorts of methods or applications, but there’s a lot of interdisciplinary work as well.

Among people who work on materials, there’s a mix of research methods, material types studied, and different applications. Most broadly, most people either do theory (sometimes called pen and paper theory to distinguish it from numerical work), computational work (which is also called theory sometimes), and experimental work. People who do theoretical work try to understand the phenomenology of known materials and to predict what new materials would be good candidates for experiments to be done on. Experimentalists have a wide range of specializations, ranging from materials synthesis to different characterization techniques. Often papers in this field can have 10+ co-authors because there will be 2-3 people from different groups that do synthesis, computational work, and maybe 2 or 3 characterization techniques per paper.

Theoretical work tries to understand the properties of materials by developing models for materials or by simulating their properties by using approximations to numerically solve the Schrodinger equation for the electrons in the material. Typically the properties of most solids are rooted in how their electrons behave, and “electronic structure theory” is a generic term for a range of methods that try to solve the Schrodinger equation for the electrons in a material numerically. Methods like DFT (which was much talked about on Twitter) fall into this category. There’s also work in materials design that uses database searches and machine learning methods to try to predict which existing or hypothetical materials might merit further experimental study. Some people tend to focus on applying computational methods, while other work on improving computational methods to be more accurate or to be able to handle more phenomena.

On the experimental side, some groups specialize in synthesis of materials (while also doing some characterization in their own labs), and others focus on one or two experimental techniques (such as STM, NMR, or ARPES) to try to understand what is going on in the material. These can range from setups that are in a lab room to using equipment that’s only available at a few places in the country at national labs. While theorists can work remotely from anywhere since they can use their own group’s or publicly provided computing clusters, experimentalists often have to travel to facilities throughout the country to use the unique experimental setups at different national labs.

Typically people working in these related fields are either at universities or national labs; there are also some people working in industry at semiconductor companies, start ups, or even tech companies which have a research component. A very large fraction of papers in the field is by people at a national lab or university, however. It’s not uncommon to read a paper from before about the 80s or 90s that have authors from industry, but nowadays one doesn’t encounter that so often.

In addition to there being people with many different backgrounds and research methods, there’s a huge range of types of materials that people study. An exhaustive list would be difficult, but there’s work in optoelectronics (including LEDs and photovoltaics), superconductors, topological materials, batteries, materials for quantum computing, thermoelectrics, carbon capture, hydrogen production, air and water filtering, and even things like making devices for dark matter detection.

Again, it would be difficult to provide a complete list of some of the most recent developments in the field, but I’ll provide a few examples. Recently, there has been a lot of interest in a variety of different materials classes that are in some way tunable. In this context, tunability refers to being able to easily replace one element or functional group of the system with another one that can give rise to different properties. One example of such materials are transition metal dichalcogenides (TMDs). These materials have transition metals (these are the metallic elements which have d electrons) and chalcogens (for example S, Se, Te) in a layered crystal structure. They are interesting because there’s a range of different behaviors these materials can have, ranging from superconductors to semiconductors in electron transport, and there’s also interest in their optical properties too. Another interesting feature of these materials is that you can have them in a monolayer (like graphene), and the monolayer often has different properties than the bulk material. Finally, you can put two different monolayer TMDs on top of each other to create a Moire pattern which gives rise to even more physical properties (this is similar to twisted bilayer graphene).

Metal-halide perovskites are another very hot material, primarily for their optical properties. Metal-oxide perovskites have been well studied and used for different applications historically (and the original high temperature cuprate superconductors fall into this category), but around 2010 some of the first measurements on metal-halide perovskites were done establishing them as solar cell materials. They have since gone on to have a very rapid rise in their efficiency, now rivaling some of the top performing materials. Metal-halide perovskites are tunable because they have 3 different components to their structure that can be changed. They have the chemical formula ABX3 where A can be an organic molecule cation, or something like cesium, B can be a transition metal or something like tin or lead, and X is a halogen (like Cl, Br, I). Thus, there’s a large number of possible structure types that one can make, and optimizing the chemical composition and synthesis methods has helped lead to the large increase in their efficiency. One exciting aspect of metal-halide perovskites is that their synthesis is a lot easier than things like crystalline silicon since they are often able to be made in solution. One drawback of metal-halide perovskites is that basically all of the promising ones for solar cells have lead in it, which is toxic so there are concerns about being able to prevent it from getting out of the material or being able to use a different element instead. Metal-halide perovskites can be tuned to absorb light at very different energies of light. This property means that you can make some of them absorb light at low, intermediate, and high energies of light, enabling a larger fraction of solar energy to be captured by the material. This sort of device is referred to as a tandem solar cell. Another use for metal-halide perovskites is for LEDs, and for this application often layered perovskites are used. These materials have perovskite-like layers separated by large organic cations and going from the bulk solid to a layered structure modifies the properties of the material just like with TMDs.

Finally, one class of material that is less common in physics and materials science research but is common in chemical and chemical engineering is metal-organic frameworks. These materials have metal nodes which are connected to each other by organic molecules. There is a huge range of possible structure types that have already by synthesized, and many more that have been hypothesized to exist. They are often used for gas separations applications like carbon capture, hydrogen storage, or other pollution reduction applications (including sometimes water purification). They typically have very large pores, meaning that gasses can easily pass through the materials. In this sense they are sort of like sponges because air can go through them, and then if they are designed properly, carbon dioxide or other molecules in the air can be captured while the rest of the air is able to go through it. Additionally, these materials have attracted interest for catalysis and photocatalysis because they can have metals that are known to catalyze chemical reactions in them.

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With regards to room temperature superconductors, once you have the suitable conductor, I would think one might then focus on the insulating material in order to protect the conductor from external and internal photon and electron interactions. Perhaps this would be a high Z material (tungsten or uranium, perhaps) with a dense and non reactive cloud. The conductor may be crystalline in nature, but the insulator might be amorphous. If this is achievable, then quantum computing can be made much simpler.

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It was hump day, so Putin threatened to use nuclear weapons to continue his war on Ukraine. Can somebody help me? I’ve lost count of how many times Putin has threatened to use nuclear weapons. I know it’s more than 10 fingers.

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The custom trade in too much journalism is context-free. An article citing a supposedly huge budget number is seldom put into the context of the total budget. Why? Because that number often represents the opposite, a very small portion of the total budget. An article cites the rise of the Chinese Navy, but the provisional reach of that navy is 1,000 nautical miles, and there is no network of military bases outside the realm of the South China Sea. The constant threat of a Chinese invasion of Taiwan doesn’t take into account the logistical fallout, supply lines blocked, cut, or destroyed. My guess is there are many things with kill switches or booby traps on more infrastructure and industry than TSMC’s ASML chip lithography machines. Articles glibly state nuclear power and proliferation are the magic wand that will solve the fossil fuel problem and climate change. There is little discussion of the millennials-long problem of nuclear waste. Where are these advocates maps and predictions of the thousands of earthquakes that annually occur on the planet? No scientist can predict earthquakes and associated tsunamis, nor their intensity, nor their locations, with any certainty whatsoever. Generating nuclear waste requires absolute certainty of manifold problems: geological events, landslides, geopolitical wars/conflicts, etc. Nuclear waste is an unforgiving crucible with millennials-long future. Seventy-five years of nuclear is history is not a realistic sampling of the safety of nuclear waste. We rue the proliferation of nuclear weapons yet propose creating more soft targets of nuclear facilities and buried nuclear waste for terrorists.

There is an ample supply of context-free, bottom-of-the-birdcage journalism. We live an e-existence of digital devices and impressive technologies, but there is a lack of the most important context: We live in a physical, unforgiving environment:

https://www.technologyreview.com/2024/04/24/1091137/quartz-cobalt-book-reviews-ed-conway-oliver-franklin-wallis-siddharth-kara/

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The custom trade in too much journalism is context-free. An article citing a supposedly huge budget number is seldom put into the context of the total budget. Why? Because that number often represents the opposite, a very small portion of the total budget. An article cites the rise of the Chinese Navy, but the provisional reach of that navy is 1,000 nautical miles, and there is no network of military bases outside the realm of the South China Sea. The constant threat of a Chinese invasion of Taiwan doesn’t take into account the logistical fallout, supply lines blocked, cut, or destroyed. My guess is there are many things with kill switches or booby traps on more infrastructure and industry than TSMC’s ASML chip lithography machines. Articles glibly state nuclear power and proliferation are the magic wand that will solve the fossil fuel problem and climate change. There is little discussion of the millennials-long problem of nuclear waste. Where are these advocates maps and predictions of the thousands of earthquakes that annually occur on the planet? No scientist can predict earthquakes and associated tsunamis, nor their intensity, nor their locations, with any certainty whatsoever. Generating nuclear waste requires absolute certainty of manifold problems: geological events, landslides, geopolitical wars/conflicts, etc. Nuclear waste is an unforgiving crucible with millennials-long future. Seventy-five years of nuclear is history is not a realistic sampling of the safety of nuclear waste. We rue the proliferation of nuclear weapons yet propose creating more soft targets of nuclear facilities and buried nuclear waste for terrorists.

There is an ample supply of context-free, bottom-of-the-birdcage journalism. We live an e-existence of digital devices and impressive technologies, but there is a lack of the most important context: We live in a physical, unforgiving environment:

https://www.technologyreview.com/2024/04/24/1091137/quartz-cobalt-book-reviews-ed-conway-oliver-franklin-wallis-siddharth-kara/

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