One of the common criticisms of new housing is that it's designed for rich people and that it does nothing to help the housing situation of average citizens. The YIMBY response to this is, "Well, yes, it does actually, because supply eases overall housing pressures and because of the filtering effect." This is the process whereby housing becomes gradually more affordable and available to people as new housing is built and vacancies are created. But most people don't like this explanation. It feels slow and indirect.

Here's something that might help.

In this recent study, researchers looked at the downstream effects of a new condominium tower in Honolulu called The Central Ala Moana. Completed in 2021, the building contains 512 units, of which 60% are income-restricted (310 units) and 40% are market-rate (202 units). It was developed under a state affordable-housing program that gave the developer height and density bonuses, plus fee waivers totalling about $13 million in exchange for delivering income-restricted units. (In my opinion, this is directionally preferable to unfunded inclusionary zoning mandates.)

Using address-history microdata, the researchers tracked who moved into the new condominium tower, and constructed detailed vacancy chains across multiple rounds of moves. Here's what they discovered:

Among documented vacancies, the 202 market-rate units produced 87 downstream vacancies (0.43 vacancies per initial unit), while the 310 income-restricted units produced 90 (0.29 vacancies per unit). Thus, market-rate units are more likely to generate a downstream vacancy. The main mechanism is new household formation: movers into income-restricted units are more likely to be a newly formed household, leaving family or roommates at the prior address and thus preventing a vacancy from being created.

In absolute numbers, they found that the completion of the building induced more than 500 local vacancies in the three years after construction, by setting off a chain of moves. Importantly, the researchers also found that the homes being vacated were, on average, about 40% less expensive than those in The Central. So even though a new building may be more expensive than the existing housing stock (which is generally the case or else the development wouldn't happen), it does generate benefits.

It eases overall housing supply constraints and expands affordability in the local housing market.

Cover photo by Michael Olsen on Unsplash

Engaging in physical activity is unequivocally associated with improved health outcomes. But are certain physical activities better than others? And what might the implications be for how we design our cities?

Here is a brand new study that examined the relationship between specific types of physical activity and the risk of death, using two large cohort studies with more than 30 years of self-reported data.

The study included information on walking, jogging, running, cycling (including stationary machines), lap swimming, tennis, climbing flights of stairs, rowing, and weight training.

It's important to note that this is an observational study using self-reported data. There are limitations to this. One question mark is around intensity. When someone reports swimming for an hour, it could be vigorous or casual. And the researchers note that long, low-intensity physical activities could bias the observed associations toward the null.

With this caveat out of the way, here's what they found:

Their two key findings were that (1) most physical activities lower mortality rates in a non-linear way when you do more of them, and (2) mixing different physical activities is associated with lower mortality, independent of total activity levels. Variety is good.

Interestingly enough, the most effective activity at lowering overall mortality is the simplest one: walking. It was found to reduce all-cause mortality by about 17%. This is the difference, or maximum observed benefit, between the highest walking group and a sedentary baseline.

Once again, the data clearly shows that walkable cities can help produce meaningfully better health outcomes. So, if, like me, you subscribe to the philosophy that there's no greater luxury in life than our health, well, then there's perhaps no greater luxury than living in a walkable city.

Cover photo by Alain ROUILLER on Unsplash

One of the basic principles behind rent control policies is that you're trying to make housing more affordable for some, while at the same time more expensive for others. Economics is the study of choice, and this is a choice, whether it gets talked about or not. Previously, we spoke about a memo from Howard Marks where he describes the impact of rent control in New York City. In economic terms, that impact looks like this:

• Some people who couldn't afford to live in New York City if rents were set by the free market get the opportunity to live in the city (their housing is more affordable)

• Other people who would like to live in New York City and could afford higher rents can't because there are no available apartments (rent controls reduce housing supply)

• And lastly, landlords with unregulated apartments can command higher rents than would be the case if new housing supply were not being discouraged (their housing is more expensive)

Today, let's talk about a recent research paper (June 2025) published in the Journal of Housing Economics called, "Rent control and the supply of affordable housing." What the authors discovered was the following:

• Restrictive rent control reforms are associated with a 10% reduction in the total number of rental units available in a city

• Restrictive rent control reforms led to an increase in the availability of units affordable to extremely low-income households

• This was offset by a decline in the availability of units to other income groups, particularly those at slightly higher affordability thresholds

Once again, we see the economic trade-offs inherent in supply-side interventions like rent control. It's better for some and worse for others. However, governments tend to favor it because it's "free" to them; the costs are borne by landlords and renters at higher affordability thresholds. I'll let all of you comment on whether you think this is good or bad, but regardless, I think it's crucial that we acknowledge the trade-offs being made.

Cover photo by Benjamin Ashton on Unsplash

One of the common criticisms of new housing is that it's designed for rich people and that it does nothing to help the housing situation of average citizens. The YIMBY response to this is, "Well, yes, it does actually, because supply eases overall housing pressures and because of the filtering effect." This is the process whereby housing becomes gradually more affordable and available to people as new housing is built and vacancies are created. But most people don't like this explanation. It feels slow and indirect.

Here's something that might help.

In this recent study, researchers looked at the downstream effects of a new condominium tower in Honolulu called The Central Ala Moana. Completed in 2021, the building contains 512 units, of which 60% are income-restricted (310 units) and 40% are market-rate (202 units). It was developed under a state affordable-housing program that gave the developer height and density bonuses, plus fee waivers totalling about $13 million in exchange for delivering income-restricted units. (In my opinion, this is directionally preferable to unfunded inclusionary zoning mandates.)

Using address-history microdata, the researchers tracked who moved into the new condominium tower, and constructed detailed vacancy chains across multiple rounds of moves. Here's what they discovered:

Among documented vacancies, the 202 market-rate units produced 87 downstream vacancies (0.43 vacancies per initial unit), while the 310 income-restricted units produced 90 (0.29 vacancies per unit). Thus, market-rate units are more likely to generate a downstream vacancy. The main mechanism is new household formation: movers into income-restricted units are more likely to be a newly formed household, leaving family or roommates at the prior address and thus preventing a vacancy from being created.

In absolute numbers, they found that the completion of the building induced more than 500 local vacancies in the three years after construction, by setting off a chain of moves. Importantly, the researchers also found that the homes being vacated were, on average, about 40% less expensive than those in The Central. So even though a new building may be more expensive than the existing housing stock (which is generally the case or else the development wouldn't happen), it does generate benefits.

It eases overall housing supply constraints and expands affordability in the local housing market.

Cover photo by Michael Olsen on Unsplash

Engaging in physical activity is unequivocally associated with improved health outcomes. But are certain physical activities better than others? And what might the implications be for how we design our cities?

Here is a brand new study that examined the relationship between specific types of physical activity and the risk of death, using two large cohort studies with more than 30 years of self-reported data.

The study included information on walking, jogging, running, cycling (including stationary machines), lap swimming, tennis, climbing flights of stairs, rowing, and weight training.

It's important to note that this is an observational study using self-reported data. There are limitations to this. One question mark is around intensity. When someone reports swimming for an hour, it could be vigorous or casual. And the researchers note that long, low-intensity physical activities could bias the observed associations toward the null.

With this caveat out of the way, here's what they found:

Their two key findings were that (1) most physical activities lower mortality rates in a non-linear way when you do more of them, and (2) mixing different physical activities is associated with lower mortality, independent of total activity levels. Variety is good.

Interestingly enough, the most effective activity at lowering overall mortality is the simplest one: walking. It was found to reduce all-cause mortality by about 17%. This is the difference, or maximum observed benefit, between the highest walking group and a sedentary baseline.

Once again, the data clearly shows that walkable cities can help produce meaningfully better health outcomes. So, if, like me, you subscribe to the philosophy that there's no greater luxury in life than our health, well, then there's perhaps no greater luxury than living in a walkable city.

Cover photo by Alain ROUILLER on Unsplash

One of the basic principles behind rent control policies is that you're trying to make housing more affordable for some, while at the same time more expensive for others. Economics is the study of choice, and this is a choice, whether it gets talked about or not. Previously, we spoke about a memo from Howard Marks where he describes the impact of rent control in New York City. In economic terms, that impact looks like this:

• Some people who couldn't afford to live in New York City if rents were set by the free market get the opportunity to live in the city (their housing is more affordable)

• Other people who would like to live in New York City and could afford higher rents can't because there are no available apartments (rent controls reduce housing supply)

• And lastly, landlords with unregulated apartments can command higher rents than would be the case if new housing supply were not being discouraged (their housing is more expensive)

Today, let's talk about a recent research paper (June 2025) published in the Journal of Housing Economics called, "Rent control and the supply of affordable housing." What the authors discovered was the following:

• Restrictive rent control reforms are associated with a 10% reduction in the total number of rental units available in a city

• Restrictive rent control reforms led to an increase in the availability of units affordable to extremely low-income households

• This was offset by a decline in the availability of units to other income groups, particularly those at slightly higher affordability thresholds

Once again, we see the economic trade-offs inherent in supply-side interventions like rent control. It's better for some and worse for others. However, governments tend to favor it because it's "free" to them; the costs are borne by landlords and renters at higher affordability thresholds. I'll let all of you comment on whether you think this is good or bad, but regardless, I think it's crucial that we acknowledge the trade-offs being made.

Cover photo by Benjamin Ashton on Unsplash