Michael Wiebe
@michaelwiebe.bsky.social
Economics (UBC), yimby, replication, effective altruism, data science.
Social insurance = redistribution?
November 11, 2025 at 2:56 AM
Social insurance = redistribution?
When rich people move in, but zoning allows only detached houses, we just get nicer mansions while poor people move away.
If zoning allowed apartments, the housing stock could increase with population, so we get gentrification without displacement.
If zoning allowed apartments, the housing stock could increase with population, so we get gentrification without displacement.
November 10, 2025 at 6:01 PM
When rich people move in, but zoning allows only detached houses, we just get nicer mansions while poor people move away.
If zoning allowed apartments, the housing stock could increase with population, so we get gentrification without displacement.
If zoning allowed apartments, the housing stock could increase with population, so we get gentrification without displacement.
Why do you think developers are uniquely responsible for promoting integration? If integration is a social good, shouldn't all of us be responsible for providing it?
November 9, 2025 at 7:32 PM
Why do you think developers are uniquely responsible for promoting integration? If integration is a social good, shouldn't all of us be responsible for providing it?
No, cost/benefit is measured in terms of welfare or well-being, not simply in monetary terms. If society thinks that segregation is harmful, then we should pay to reduce it. But taxing developers (and hence new housing) is the wrong way to do that. Better to use a broad tax base and fund vouchers.
November 9, 2025 at 7:29 PM
No, cost/benefit is measured in terms of welfare or well-being, not simply in monetary terms. If society thinks that segregation is harmful, then we should pay to reduce it. But taxing developers (and hence new housing) is the wrong way to do that. Better to use a broad tax base and fund vouchers.
Yes, if cost of subsidized homes <= payment to developer, that's economically equivalent to taxing developers by the net amount.
Density bonus, etc are types of payment. Best case is cost = payment.
Integration benefits can be weighed against costs of tax.
Density bonus, etc are types of payment. Best case is cost = payment.
Integration benefits can be weighed against costs of tax.
November 9, 2025 at 1:20 AM
Yes, if cost of subsidized homes <= payment to developer, that's economically equivalent to taxing developers by the net amount.
Density bonus, etc are types of payment. Best case is cost = payment.
Integration benefits can be weighed against costs of tax.
Density bonus, etc are types of payment. Best case is cost = payment.
Integration benefits can be weighed against costs of tax.
It's equivalent to a tax. I discuss funded IZ in the article.
November 8, 2025 at 9:03 PM
It's equivalent to a tax. I discuss funded IZ in the article.
Moreover, we also have to think about the counterfactual. Without upzoning, cheap old homes will just be renovated or replaced with low-density expensive new homes. We're below the 1.67 threshold, so the stock of cheap homes decreases.
Single-family zoning = gentrification.
4/4
Single-family zoning = gentrification.
4/4
November 6, 2025 at 6:55 PM
Moreover, we also have to think about the counterfactual. Without upzoning, cheap old homes will just be renovated or replaced with low-density expensive new homes. We're below the 1.67 threshold, so the stock of cheap homes decreases.
Single-family zoning = gentrification.
4/4
Single-family zoning = gentrification.
4/4
Cities tend to allow new apartments only on top of old apartments. But we maximize the stock of cheap homes by adding apartments in expensive single-family areas, to avoid tearing down old apartments.
With transit-oriented development, this is harder to avoid.
3/
With transit-oriented development, this is harder to avoid.
3/
November 6, 2025 at 6:55 PM
Cities tend to allow new apartments only on top of old apartments. But we maximize the stock of cheap homes by adding apartments in expensive single-family areas, to avoid tearing down old apartments.
With transit-oriented development, this is harder to avoid.
3/
With transit-oriented development, this is harder to avoid.
3/
From vacancy chain studies, every new home frees up 0.6 homes in below-median-income neighborhoods.
So in general, the new building needs to be at least 1/0.6 = 1.67x bigger than the old building to maintain the stock of cheap homes.
www.buildingabundance.ca/p/vacancy-ch...
2/
So in general, the new building needs to be at least 1/0.6 = 1.67x bigger than the old building to maintain the stock of cheap homes.
www.buildingabundance.ca/p/vacancy-ch...
2/
Vacancy chains
How building expensive new homes today lowers the price of old homes today
www.buildingabundance.ca
November 6, 2025 at 6:55 PM
From vacancy chain studies, every new home frees up 0.6 homes in below-median-income neighborhoods.
So in general, the new building needs to be at least 1/0.6 = 1.67x bigger than the old building to maintain the stock of cheap homes.
www.buildingabundance.ca/p/vacancy-ch...
2/
So in general, the new building needs to be at least 1/0.6 = 1.67x bigger than the old building to maintain the stock of cheap homes.
www.buildingabundance.ca/p/vacancy-ch...
2/
Inclusionary zoning
How to fund subsidized housing using surplus land value
www.buildingabundance.ca
November 5, 2025 at 6:12 PM
In mansion district Shaughnessy, land values increased 5x, just due to rising demand to live in Vancouver. There are no upzonings, since the neighborhood is heritage protected.
IZ does nothing to capture this land value. LVT works, because it's unconditional.
2/
IZ does nothing to capture this land value. LVT works, because it's unconditional.
2/
November 5, 2025 at 6:12 PM
In mansion district Shaughnessy, land values increased 5x, just due to rising demand to live in Vancouver. There are no upzonings, since the neighborhood is heritage protected.
IZ does nothing to capture this land value. LVT works, because it's unconditional.
2/
IZ does nothing to capture this land value. LVT works, because it's unconditional.
2/
Doesn't this answer your question? p.17
November 5, 2025 at 2:34 AM
Doesn't this answer your question? p.17
Land values increased 5x in a mansion district. IZ cannot capture this.
michaelwiebe.com/blog/2025/09...
michaelwiebe.com/blog/2025/09...
November 4, 2025 at 5:35 PM
Land values increased 5x in a mansion district. IZ cannot capture this.
michaelwiebe.com/blog/2025/09...
michaelwiebe.com/blog/2025/09...
Keep in mind: IZ only captures land value when redevelopment occurs. A land value tax captures land value unconditionally.
November 4, 2025 at 5:32 PM
Keep in mind: IZ only captures land value when redevelopment occurs. A land value tax captures land value unconditionally.
But, but, we have to preserve the 'neighborhood character' for people who own a Porsche and a BMW!
November 4, 2025 at 4:53 PM
But, but, we have to preserve the 'neighborhood character' for people who own a Porsche and a BMW!
>Typically, local governments apply IZ bylaws with an accompanying increase in as-of-right building densities as informed by a financial feasibility analysis,10 in order to offset the costs to the developer of providing the affordable units.
So they define IZ as DB-IZ.
So they define IZ as DB-IZ.
November 4, 2025 at 3:34 PM
>Typically, local governments apply IZ bylaws with an accompanying increase in as-of-right building densities as informed by a financial feasibility analysis,10 in order to offset the costs to the developer of providing the affordable units.
So they define IZ as DB-IZ.
So they define IZ as DB-IZ.
I don't get this distinction. They both do the same thing.
In my terminology, density bonus is a type of IZ.
In my terminology, density bonus is a type of IZ.
November 4, 2025 at 3:25 PM
I don't get this distinction. They both do the same thing.
In my terminology, density bonus is a type of IZ.
In my terminology, density bonus is a type of IZ.
And also nothing is happening, so no one believes it means much.
November 4, 2025 at 2:26 AM
And also nothing is happening, so no one believes it means much.
My understanding is that TOA just means the city can't reject developments based on height. The city can still do IZ.
November 4, 2025 at 2:00 AM
My understanding is that TOA just means the city can't reject developments based on height. The city can still do IZ.