Michael Wiebe
@michaelwiebe.bsky.social
Economics (UBC), yimby, replication, effective altruism, data science.
Single-family zoning causes gentrification.
November 10, 2025 at 6:01 PM
Single-family zoning causes gentrification.
One worry about densifying is that old cheap homes are torn down and replaced with expensive new homes.
But adding new homes frees up old homes, via vacancy chains. A new 100-unit building could replace 60 old homes and still break even on the total stock of cheap homes.
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But adding new homes frees up old homes, via vacancy chains. A new 100-unit building could replace 60 old homes and still break even on the total stock of cheap homes.
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November 6, 2025 at 6:55 PM
One worry about densifying is that old cheap homes are torn down and replaced with expensive new homes.
But adding new homes frees up old homes, via vacancy chains. A new 100-unit building could replace 60 old homes and still break even on the total stock of cheap homes.
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But adding new homes frees up old homes, via vacancy chains. A new 100-unit building could replace 60 old homes and still break even on the total stock of cheap homes.
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Important fact about inclusionary zoning: it's a *partial* value capture mechanism, because it applies only conditional on development. Landowners can avoid IZ value capture by doing nothing, and still watch their land value increase. Land value tax solves this.
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November 5, 2025 at 6:12 PM
Important fact about inclusionary zoning: it's a *partial* value capture mechanism, because it applies only conditional on development. Landowners can avoid IZ value capture by doing nothing, and still watch their land value increase. Land value tax solves this.
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Discuss: is it better to under-capture land value, guaranteeing that market-rate housing is built while missing out on some subsidized homes; or over-capture and get the subsidized homes, but at the cost of higher market rents?
Ie. costs of false positives vs false negatives.
Ie. costs of false positives vs false negatives.
New post on inclusionary zoning, for my housing literature review.
IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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November 4, 2025 at 4:57 PM
Discuss: is it better to under-capture land value, guaranteeing that market-rate housing is built while missing out on some subsidized homes; or over-capture and get the subsidized homes, but at the cost of higher market rents?
Ie. costs of false positives vs false negatives.
Ie. costs of false positives vs false negatives.
Video idea: cyclists going through a stop sign at the same speed as a car doing a rolling stop.
@ohtheurbanity.bsky.social
@ohtheurbanity.bsky.social
November 4, 2025 at 2:17 AM
Video idea: cyclists going through a stop sign at the same speed as a car doing a rolling stop.
@ohtheurbanity.bsky.social
@ohtheurbanity.bsky.social
Reposted by Michael Wiebe
New post on inclusionary zoning, for my housing literature review.
IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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November 3, 2025 at 8:03 PM
New post on inclusionary zoning, for my housing literature review.
IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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New post on inclusionary zoning, for my housing literature review.
IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
1/
IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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November 3, 2025 at 8:03 PM
New post on inclusionary zoning, for my housing literature review.
IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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IZ requires developers to provide subsidized homes in their new apartment buildings. Without providing compensation to developers, this unfunded IZ is just a tax on new housing.
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How to fund subsidized housing using upzoning, a thread.
Land value capture works when zoning is (harmfully) a binding constraint on new development. Then, upzoning creates value. Land values rise, because the parcel has more uses.
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Land value capture works when zoning is (harmfully) a binding constraint on new development. Then, upzoning creates value. Land values rise, because the parcel has more uses.
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November 2, 2025 at 6:48 PM
How to fund subsidized housing using upzoning, a thread.
Land value capture works when zoning is (harmfully) a binding constraint on new development. Then, upzoning creates value. Land values rise, because the parcel has more uses.
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Land value capture works when zoning is (harmfully) a binding constraint on new development. Then, upzoning creates value. Land values rise, because the parcel has more uses.
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Reposted by Michael Wiebe
This paper gives a powerful generalization of event study models to allow an arbitrary number of events, each with a treatment dose of any sign or magnitude.
#econsky
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#econsky
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February 1, 2025 at 12:22 AM
This paper gives a powerful generalization of event study models to allow an arbitrary number of events, each with a treatment dose of any sign or magnitude.
#econsky
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#econsky
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Local control over zoning is a government failure, because restrictive zoning imposes a negative externality on non-residents who are priced out. Higher-level governments need to set zoning policy to internalize the externality.
October 31, 2025 at 5:20 PM
Local control over zoning is a government failure, because restrictive zoning imposes a negative externality on non-residents who are priced out. Higher-level governments need to set zoning policy to internalize the externality.
🚨YIMBY research wanted🚨
Show quantitatively how a demand cascade works: when high-end demand increases, it spills over to the low-end market, so both high- and low-end prices increase.
Use a Bartik demand shifter for college-educated workers. Measure quality using home age.
Show quantitatively how a demand cascade works: when high-end demand increases, it spills over to the low-end market, so both high- and low-end prices increase.
Use a Bartik demand shifter for college-educated workers. Measure quality using home age.
October 31, 2025 at 12:23 AM
🚨YIMBY research wanted🚨
Show quantitatively how a demand cascade works: when high-end demand increases, it spills over to the low-end market, so both high- and low-end prices increase.
Use a Bartik demand shifter for college-educated workers. Measure quality using home age.
Show quantitatively how a demand cascade works: when high-end demand increases, it spills over to the low-end market, so both high- and low-end prices increase.
Use a Bartik demand shifter for college-educated workers. Measure quality using home age.
One misconception about IZ is that the market-rate homes in an IZ building cross-subsidize the non-market homes. But this isn't how tax incidence works. Developers cannot set above-market rents, because renters would simply find cheaper rents elsewhere.
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October 30, 2025 at 5:52 PM
One misconception about IZ is that the market-rate homes in an IZ building cross-subsidize the non-market homes. But this isn't how tax incidence works. Developers cannot set above-market rents, because renters would simply find cheaper rents elsewhere.
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Moretti 2021 uses an IV for cluster size based on the number of inventors in the same firm in other cities. But this has a coding error, and correcting the error gives a null result.
But the idea sounds like shift-share IV, so I tried that, and it works:
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But the idea sounds like shift-share IV, so I tried that, and it works:
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October 29, 2025 at 8:10 PM
Moretti 2021 uses an IV for cluster size based on the number of inventors in the same firm in other cities. But this has a coding error, and correcting the error gives a null result.
But the idea sounds like shift-share IV, so I tried that, and it works:
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But the idea sounds like shift-share IV, so I tried that, and it works:
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LMW are testing whether we find the expected subgroup pattern, when using supply elasticity estimates from the literature to split the sample into Low- and High-elasticity subgroups, and estimating a new elasticity ψ: namely, ψ_L < ψ_H.
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LMW are making two contributions:
1) a substantive point about supply elasticities behaving as expected in subgroups.
2) a methodological contribution about identifying relative supply elasticities without a standard instrument.
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1) a substantive point about supply elasticities behaving as expected in subgroups.
2) a methodological contribution about identifying relative supply elasticities without a standard instrument.
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This paper was making the rounds, but did you notice it has a key contradiction?
They divide cities into two groups (high and low housing supply constraints), and estimate the supply elasticity—how much quantities change in response to prices. Result: no difference!
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They divide cities into two groups (high and low housing supply constraints), and estimate the supply elasticity—how much quantities change in response to prices. Result: no difference!
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October 28, 2025 at 10:37 PM
LMW are testing whether we find the expected subgroup pattern, when using supply elasticity estimates from the literature to split the sample into Low- and High-elasticity subgroups, and estimating a new elasticity ψ: namely, ψ_L < ψ_H.
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LMW are making two contributions:
1) a substantive point about supply elasticities behaving as expected in subgroups.
2) a methodological contribution about identifying relative supply elasticities without a standard instrument.
1/
1) a substantive point about supply elasticities behaving as expected in subgroups.
2) a methodological contribution about identifying relative supply elasticities without a standard instrument.
1/
This paper was making the rounds, but did you notice it has a key contradiction?
They divide cities into two groups (high and low housing supply constraints), and estimate the supply elasticity—how much quantities change in response to prices. Result: no difference!
1/
They divide cities into two groups (high and low housing supply constraints), and estimate the supply elasticity—how much quantities change in response to prices. Result: no difference!
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October 28, 2025 at 10:35 PM
LMW are making two contributions:
1) a substantive point about supply elasticities behaving as expected in subgroups.
2) a methodological contribution about identifying relative supply elasticities without a standard instrument.
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1) a substantive point about supply elasticities behaving as expected in subgroups.
2) a methodological contribution about identifying relative supply elasticities without a standard instrument.
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Reposted by Michael Wiebe
To people looking for a home today, writes @dannyoleksiuk.bsky.social, it matters a great deal whether that home is built next year, or in ten. Re-legalizing small apartment buildings throughout our cities would create more homes faster. www.sightline.org/2025/10/28/t...
To Build Fast, Think Small | Sightline Institute
How re-legalizing small apartment buildings would spur the homes city dwellers need now.
www.sightline.org
October 28, 2025 at 5:37 PM
To people looking for a home today, writes @dannyoleksiuk.bsky.social, it matters a great deal whether that home is built next year, or in ten. Re-legalizing small apartment buildings throughout our cities would create more homes faster. www.sightline.org/2025/10/28/t...
Why not repeat this 1000 times?
A single building in Evanston will increase its total inclusionary affordable units accumulated over two decades by 130%
The Affordable Housing Special Assessment Program is amazing
The Affordable Housing Special Assessment Program is amazing
The tower will include 84 inclusionary housing units at 60% AMI, nearly 20 more than Evanston has built in the 18 years its ordinance has existed
The lead developer is Vermilion Development and the tower is designed by Evanstonian James Michaels of SCB
Story TK
The lead developer is Vermilion Development and the tower is designed by Evanstonian James Michaels of SCB
Story TK
October 28, 2025 at 4:00 PM
Why not repeat this 1000 times?
Reposted by Michael Wiebe
Do young people face higher shelter costs than their older compatriots? @lausterna.bsky.social and I look into this question and the underlying mechanisms that can lead to age disparities in shelter costs.
Age Disparity in Shelter Cost per Room – Mountain Doodles
Housing sometimes feels like a generational issue – because it is.
doodles.mountainmath.ca
October 27, 2025 at 3:49 PM
Do young people face higher shelter costs than their older compatriots? @lausterna.bsky.social and I look into this question and the underlying mechanisms that can lead to age disparities in shelter costs.
Simpson's paradox, YIMBY edition:
Increasing the supply of housing reduces the price of both new and old homes; but by shifting the composition of the housing stock towards (more-expensive) new homes, the average price increases.
Increasing the supply of housing reduces the price of both new and old homes; but by shifting the composition of the housing stock towards (more-expensive) new homes, the average price increases.
October 22, 2025 at 11:38 PM
Simpson's paradox, YIMBY edition:
Increasing the supply of housing reduces the price of both new and old homes; but by shifting the composition of the housing stock towards (more-expensive) new homes, the average price increases.
Increasing the supply of housing reduces the price of both new and old homes; but by shifting the composition of the housing stock towards (more-expensive) new homes, the average price increases.
Rollet 2025 Fig 3b shows that the average upzoning raises FAR by 1.0, but only increases built FAR by 0.10 over ten years.
Upshot: theoretical zoned capacity needs to be at least 10x bigger than the target amount of housing.
Upshot: theoretical zoned capacity needs to be at least 10x bigger than the target amount of housing.
October 22, 2025 at 5:16 PM
Rollet 2025 Fig 3b shows that the average upzoning raises FAR by 1.0, but only increases built FAR by 0.10 over ten years.
Upshot: theoretical zoned capacity needs to be at least 10x bigger than the target amount of housing.
Upshot: theoretical zoned capacity needs to be at least 10x bigger than the target amount of housing.
Density bonus inclusionary zoning is win-win: we get lower market-rate prices and more subsidized housing.
Upshot: we should tile the city with IZ apartments, to minimize prices and maximize the number of subsidized homes.
Upshot: we should tile the city with IZ apartments, to minimize prices and maximize the number of subsidized homes.
October 21, 2025 at 9:09 PM
Density bonus inclusionary zoning is win-win: we get lower market-rate prices and more subsidized housing.
Upshot: we should tile the city with IZ apartments, to minimize prices and maximize the number of subsidized homes.
Upshot: we should tile the city with IZ apartments, to minimize prices and maximize the number of subsidized homes.
Has there ever been a proactive PHIMBY? Someone who calls for tiling the city with public housing.
In practice, I've only ever seen reactive PHIMBYs, who use public housing as a reason to oppose new housing.
In practice, I've only ever seen reactive PHIMBYs, who use public housing as a reason to oppose new housing.
October 20, 2025 at 9:52 PM
Has there ever been a proactive PHIMBY? Someone who calls for tiling the city with public housing.
In practice, I've only ever seen reactive PHIMBYs, who use public housing as a reason to oppose new housing.
In practice, I've only ever seen reactive PHIMBYs, who use public housing as a reason to oppose new housing.
October 19, 2025 at 9:55 PM
Inclusionary zoning can be funded by tax exemptions, reduced parking requirements, permit fast-tracking, or density bonuses.
Note: the first three are pure costs, but density is a benefit in itself, by lowering housing prices.
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Note: the first three are pure costs, but density is a benefit in itself, by lowering housing prices.
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October 17, 2025 at 7:16 PM
Inclusionary zoning can be funded by tax exemptions, reduced parking requirements, permit fast-tracking, or density bonuses.
Note: the first three are pure costs, but density is a benefit in itself, by lowering housing prices.
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Note: the first three are pure costs, but density is a benefit in itself, by lowering housing prices.
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