Friday, November 14, 2025

Beyond rent: Shared houses in Tokyo offer lifestyle, safety, and community



Text-mining 1,374 property listings reveals that Tokyo’s shared houses are marketed as lifestyle-driven homes prioritizing comfort and connection over affordability



Shibaura Institute of Technology

Distribution of Shared Houses and Rental Prices Across Tokyo 

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The maps illustrate differences in rental market prices (a) and the number of shared houses (b) across Tokyo’s municipalities. While rents are highest within the 23 central wards, shared houses are also concentrated in these areas, indicating that accessibility and lifestyle appeal outweigh cost in shaping their distribution.

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Credit: Professor Yuno Tanaka from Shibaura Institute of Technology, Tokyo





Rapid social and demographic change has reshaped how people live and connect in cities. In Tokyo, where urban density meets growing individualization, a new form of collective housing—shared houses—is redefining what home means. To understand how these spaces are marketed and perceived, researchers analyzed the descriptions of 1,374 shared houses listed by property suppliers on a major real estate website, uncovering how shared living is framed as a lifestyle choice rather than a cost-saving one.

The study, conducted by Associate Professor Yuno Tanaka from the Shibaura Institute of Technology, Tokyo, in collaboration with Dr. Kashin Sugishita from the Institute of Science Tokyo, applies large-scale text-mining analysis to explore the narratives used by property suppliers. Their findings, published in Volume 169 of the journal Cities, on October 8, 2025, reveal how the language of marketing reflects the evolving social values of urban life.

“We text-mined supplier descriptions for 1,374 properties in Tokyo—identifying 11 promotional themes—and found that shared houses are marketed as lifestyle products that emphasize safety, community, and convenience rather than cheap rent,” says Prof. Tanaka

The researchers extracted descriptive texts from Hitsuji Real Estate, a major website featuring shared houses, and used a combination of topic modeling, co-occurrence network analysis, and correspondence analysis to detect patterns across property listings. Eleven thematic clusters emerged, including “enjoyment of shared living,” “female-only and safety,” “convenience of the surrounding area,” and “common spaces.”

The results painted a diverse and nuanced picture of Tokyo’s shared housing market. Roughly half of the listed properties were mixed-sex, while nearly half were female-only—indicating both inclusivity and gender-specific considerations in housing demand. The analysis further revealed that properties near train stations frequently emphasized accessibility and neighborhood convenience, whereas those located farther away highlighted natural surroundings, interior comfort, and social interaction.

Interestingly, rental affordability was rarely mentioned, contradicting common assumptions that shared housing primarily appeals to those seeking cheaper rent. Instead, suppliers promoted experiential and emotional benefits—such as comfort, connection, and personal growth—suggesting a shift toward what economists call an “experience economy” in the housing sector.

“As individualization advances, shared houses offer community, safety, and move-in ease rather than only price relief,” explains Prof. Tanaka.  “Our study shows how these values are strategically constructed by suppliers, expanding diverse living options in dense cities.”

The study’s implications extend beyond Tokyo. By analyzing how property descriptions shape perceptions of shared housing, the research demonstrates how text-mining approaches can support smarter, data-driven housing recommendations.

“In addition to conventional home searches that filter by price or location, analyzing supplier-written listing descriptions can help match properties with seekers’ preferences and reduce mismatches in property selection,” says Prof. Tanaka.

Such analyses could also inform urban regeneration strategies. The authors suggest that promoting underused properties through lifestyle-oriented narratives can bring new life to buildings in less accessible areas, potentially contributing to the revitalization of local communities.

“By enabling flexible choice among a diverse range of housing options, homes that have until now stood vacant due to disadvantages—such as poor accessibility—can be brought back into use,” notes Prof. Tanaka. “This could help rejuvenate neighborhoods and promote more inclusive urban living.”

Overall, the study highlights a subtle yet powerful transformation in how housing is conceived and communicated. As Tokyo—and other global cities—grapples with aging populations, rising single-person households, and urban crowding, shared houses are emerging as a symbol of balance between privacy and community, convenience, and character. By bridging data science and urban sociology, this research underscores that the future of city living may depend as much on how homes are described as on how they are designed.

 

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About Shibaura Institute of Technology (SIT), Japan

Shibaura Institute of Technology (SIT) is a private university with campuses in Tokyo and Saitama. Since the establishment of its predecessor, Tokyo Higher School of Industry and Commerce, in 1927, it has maintained “learning through practice” as its philosophy in the education of engineers. SIT was the only private science and engineering university selected for the Top Global University Project sponsored by the Ministry of Education, Culture, Sports, Science and Technology and had received support from the ministry for 10 years starting from the 2014 academic year. Its motto, “Nurturing engineers who learn from society and contribute to society,” reflects its mission of fostering scientists and engineers who can contribute to the sustainable growth of the world by exposing their over 9,500 students to culturally diverse environments, where they learn to cope, collaborate, and relate with fellow students from around the world.

Website: https://www.shibaura-it.ac.jp/en/

About Associate Professor Yuno Tanaka from SIT, Japan

Yuno Tanaka is an Associate Professor at the Department of Civil Engineering, Shibaura Institute of Technology, Tokyo, Japan. She holds a Ph.D. in Architecture from Graduate School of Engineering, Kyoto University. With over eight years of teaching experience, she has published 14 peer-reviewed papers and received five major awards, including the 2022 Tokyo Institute of Technology Engineering Education Award. Her research focuses on social infrastructure, urban and architectural planning, and community-based housing design, exploring how spatial formation and shared living models contribute to sustainable urban development.

  

Cheaper cars pollute more than expensive cars, leading to emissions inequality


Lower-income individuals are more likely to own cheaper, higher-emitting vehicles and, therefore, contribute disproportionately to their local urban air pollution



University of Birmingham





More expensive cars emit lower levels of pollution - meaning that motorists owning cheaper, higher-emitting vehicles contribute disproportionately to their local urban air quality problems, a new study reveals.

Research by University of Birmingham scientists highlights a previously overlooked inequality - that lower-income individuals are more likely to own cheaper, higher-emitting vehicles and, therefore, contribute disproportionately to their local urban air pollution.

Publishing their findings today (14 Nov) in Journal of Cleaner Production, the researchers’ analysis suggests that spending an additional £10,000 on a diesel vehicle is associated with a more than 40% reduction in nitrogen oxide (NOx), emissions per litre of diesel.

Their discovery reverses the usual pattern, where wealthy households typically cause more greenhouse gas emissions through higher consumption.

Scientists analysed over 50,000 vehicles using advanced remote sensing technology measuring in real-time emissions from vehicles on the city’s streets.

They combined machine learning-based price estimation with real-world emission data to connect pricier vehicles and lower pollutant emissions — particularly NO₂, NOx, carbon monoxide (CO), and particulate matter (PM).

The research was supported by the Natural Environment Research Council (NERC) via the WM-Air project. The researchers report that:

  • Higher-priced vehicles emit significantly fewer pollutants, even within the same Euro emission class. Average NOx emissions are approximately 8.8 g/litre of diesel for £5,000 cars, compared with 5.6 g/litre for £15,000 cars.
  • Diesel vehicles show greater emission reductions per £1,000 increase in price than petrol vehicles - for every additional £1,000 spent on a diesel car, nitrogen dioxide (NO₂) emissions decrease by around 0.4 g/litre of fuel.
  • Older diesel models (Euro 5) exhibit emission reductions 1.5 times steeper with price than newer Euro 6 models, suggesting that price is a stronger proxy for emissions in older vehicles.

Report co-author Professor Francis Pope from the University of Birmingham said: "Our study provides the first clear evidence to support vehicle price being a reliable indicator of emission performance - powerfully illustrating how citizens’ economic capacity can directly influence environmental outcomes and urban air quality.

“Individuals from lower-income households may be more likely to own older, cheaper, and higher-emitting vehicles — contributing disproportionately to local air pollution.”

The study calls for policy makers to take several actions to help reduce emissions while promoting social equity. These include:

  • Progressive tax structures based on vehicle emissions and price to incentivise cleaner vehicle adoption.
  • Rebate schemes or scrappage incentives for lower-income households to accelerate the transition to cleaner transport.
  • Enhanced inspection and maintenance programmes for older vehicles may offer a cost-effective way to reduce emissions in the short term.

Report co-author Dr Omid Ghaffarpasand from the University of Birmingham said: “Our findings underscore the need for targeted policy interventions to address environmental injustice. Lower-income communities bear the brunt of local air pollution due to limited access to cleaner vehicles - exacerbating health risks and pollution exposure in disadvantaged urban areas.”

The researchers also advocate for further investigation into how vehicle affordability, emissions, and urban planning interact with each other to contribute to urban air pollution; stressing the importance of integrating socioeconomic data into transport and environmental policy frameworks to ensure equitable outcomes.

WM-Air has been working with partners to bring research organisations together with businesses, policy bodies and other actors contributing to economic development specific to their location, to deliver significant regional impact from NERC environmental science. Previous studies from WM-Air have highlighted major contributions of domestic woodburning to PM2.5 emissions, and that air pollution in the West Midlands has caused up to 2,300 premature deaths each year.

ENDS

For media enquiries please contact University of Birmingham press office - pressoffice@contacts.bham.ac.uk or +44 (0)121 414 2772.  

Notes to editor:  

Pollution and cardiac arrest: a study by the Politecnico di Milano reveals a direct link between peak air pollution and cardiac risk




Politecnico di Milano
Graphical abstract: Pollution and cardiac arrest: a study by the Politecnico di Milano reveals a direct link between peak air pollution and cardiac risk 

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Graphical abstract: Pollution and cardiac arrest: a study by the Politecnico di Milano reveals a direct link between peak air pollution and cardiac risk

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Credit: Politecnico di Milano




In Lombardy, the risk of suffering cardiac arrest may increase on days recording high levels of air pollution. This emerges from a study conducted by the Politecnico di Milano and published in the international journal Global Challenges.

Researchers analysed 37,613 cases of out-of-hospital cardiac arrest in Lombardy between 2016 and 2019 by assessing, for each episode, the daily concentrations of various pollutants (PM₂.₅, PM₁₀, NO₂, O₃ and CO) obtained from satellite data of the European Copernicus programme (ESA). The study used advanced spatio-temporal statistical models to identify the relationship between pollution peaks and increased risk of cardiac events.

“We observed a strong association with nitrogen dioxide (NO₂). Indeed, for every 10 micrograms per cubic metre increase, the risk of cardiac arrest rises by 7% over the next 96 hours,” says Amruta Umakant Mahakalkar, researcher at the Department of Electronics, Information and Bioengineering, Politecnico di Milano, and first author of the study.
“Even particulate matter PM₂.₅ and PM₁₀ present a 3% and 2.5% increase in the risk rate, respectively, on the same day of exposure.”

The effect is more pronounced in urban areas but significant associations are also observed in rural towns. The risk particularly marks an upswing in the warm months, suggesting a possible interaction between heat and pollutants. The association was also observed at levels below legal limits, suggesting that there is no safe exposure threshold.

“The link between air quality and out-of-hospital cardiac arrest is a wake-up call for local health systems,” adds Enrico Caiani, professor at the Politecnico di Milano and co-author of the study. “Emergency services should expect a potential surge in calls for action during high pollution periods.”

The study highlights how air pollution is a significant risk factor for cardiovascular health, even in the short term, and calls for this evidence to be considered in prevention policies and in the management of health emergencies.

According to the World Health Organisation, air pollution is the second environmental risk factor for non-communicable diseases. It accounts for millions of deaths worldwide each year. Lombardy, one of the most industrialised and densely populated regions in Europe, is particularly exposed to episodes of smog in winter, when system boilers are turned on and worsen air quality, along with poor atmospheric dispersion.

The results of the study provide a useful tool for institutions and emergency services. Integrating environmental data into health forecasting systems could anticipate the increase in emergency calls in the future, and thus improve resource planning.

The new CLIMA-CARE project, funded by the European Space Agency (ESA), officially kicks off today. It follows this trend of research. The project will use satellite data to analyse the impact of environmental conditions on public health and, in particular, on emergency medical services in Lombardy, both today and in the future, by creating climate projections.

Project partners include the German Aerospace Centre (DLR) - the initiative's lead partner - and the Group on Earth Observation (GEO), coordinated by the World Meteorological Organisation (WMO).

“The project will give us the opportunity to address the impact of climate change on a population-wide scale,” comments Lorenzo Gianquintieri, Researcher, Department of Electronics, Information and Bioengineering, Politecnico di Milano. “Consistently with the One-Health vision, which combines human, environmental and animal health, we promote a preventive adaptation approach based on scientific evidence.”

 

THE STUDY: A.U. Mahakalkar, E. G. Caiani, G. Stirparo, E. Picozzi, L. Gianquintieri,
Short-term effect of air pollution on OHCA in Lombardy – a case-crossover spatiotemporal study,
Global Challenges (2025), DOI: 10.1002/gch2.202500241

 

Cesarean delivery: the technique used for closing the uterus must be reconsidered




Université Laval





The most common technique used for closing the uterus after a cesarean delivery causes so many long-term complications that it’s time to question its use. That’s the conclusion reached by two world-renowned specialists in obstetrics and gynecology in an article published in a special issue of the American Journal of Obstetrics & Gynecology on cesarean delivery. The authors argue in favor of replacing the current approach with a closure technique that respects the natural anatomical structure of the uterus.

The authors, Dr Emmanuel Bujold, professor at Université Laval's Faculty of Medicine and researcher at the CHU de Québec-Université Laval Research Center, and Dr Roberto Romero, Head of the Pregnancy Research Branch at the NICHD/National Institutes of Health in US, list the many long-term complications associated with cesarean delivery and their incidence according to an exhaustive review of the scientific literature on the topic.

Complications that may arise during subsequent deliveries include abnormal attachment of the placenta to the uterus (up to 6% of women), which increases the risk of severe hemorrhage and hysterectomy; uterine rupture (up to 3%), which can lead to the death of the newborn; and prematurity (up to 28%). Women's health can also be impacted because of pelvic pain (up to 35%), postmenstrual bleeding (up to 33%), and endometriosis/adenomyosis (up to 43%).

The technique used for the past 50 years to close the uterus after a cesarean delivery involves sutures that pass through and join the uterine lining and the muscles surrounding it, explains Professor Bujold. "This method has the advantage of being simple and quick, which limits bleeding in the mother. This is undoubtedly why it has been widely adopted by obstetrician-gynecologists. However, the scar tissue produced by this type of closure does not restore the anatomical and functional integrity of the uterus, notes the scientist. When you stop to think about it, it's not surprising. For example, when someone has a laceration on their cheek, you don't close it by suturing the oral mucosa, muscles, and skin together. There's no reason to do that with the uterus.”

The closure technique proposed by Drs Bujold and Romero consists of suturing together tissues of the same type. The muscle layer of the uterus is sutured in two places, with one suture in the upper part and the other in the lower part. A third suture is made to close the envelope surrounding the organ. “We do not operate on the uterine lining so as not to interfere with its natural regeneration,” explains Bujold.

Globally, one child is born by cesarean every second, the researcher points out. In Canada, approximately 27% of children are born by cesarean, nearly double the rate observed three decades ago. “Given the high frequency of cesarean and their long-term health consequences for women, finding solutions should be considered a public health priority,” says Bujold.

The disadvantage of the approach recommended by Bujold and Romero is that it takes a little longer. “The standard closure technique takes between 2 and 3 minutes, while the one we propose takes 5 to 8 minutes. The resulting additional blood loss is marginal. Our position is that meticulous and adequate restoration of the uterine structure is more important than the speed of the procedure. The future reproductive health of women who undergo cesarean must be the priority,” concludes the researcher.