The 4-day week: making work healthier and more sustainable

  • 24 January 2024
  • Dr Orla Kelly
  • Academic, Cultural, Economic, Environmental, Health, Political


Dr Kelly led the Irish component of the first coordinated international trial of work time reduction. The trial implementation is being led by 4 Day Week Global, and Boston College is coordinating the research with academic partners, including UCD. So far, 3500 employees across 150 organisations have participated in the 6-month, company-led trials, including 188 employees from 12 firms in Ireland.

Employees on the trial have seen gains in physical and mental health, better sleep and higher rates of life satisfaction. These results have been widely covered by national and international media, and the team has briefed politicians in the US, UK and Ireland – including the Taoiseach, Minister for Public Expenditure and an Oireachtas Committee – helping direct society toward a more sustainable and healthy work culture.

Research description

The traditional five-day workweek came about in the early 20th century when unions at the time advocated reducing the six-day workweek. In the years that followed, many philosophers, social scientists and politicians predicted that new technologies and increased productivity would lead to a further reduction in work time, freeing up more time for people to invest in themselves and contribute to their communities.

This hasn’t happened yet, but there is now an increasing appetite to leverage technological advancements such as AI to move towards a healthier, more sustainable work-life balance. Organisations like the nonprofit 4 Day Week Global are advocating for work time reduction, and many companies and governments are experimenting with it. However, there are still evidence gaps on the wider impacts of these reductions.

To help address this, Dr Kelly led the Irish component of the first coordinated international trial of work time reduction (coordinated by 4 Day Week Global). Participating companies who opt into the trial offer their employees 100% of their pay for 80% of their time at work, with the proviso they continue to achieve 100% of organisational goals. The trials have been rolled out in Ireland, the US, Canada, the UK, Australia and New Zealand, with 3500 employees across 150 organisations participating, including 188 employees from 12 firms in Ireland.

To assess the organisational impacts of the 4-day work week, the team collected and analysed administrative data from companies, survey data from employees, and interviews with management and staff. They aim to understand impacts on:

  • Company productivity, profitability and carbon footprint
  • Employee burnout and job satisfaction
  • Employee health, well-being and life satisfaction
  • Pro-environmental behaviour among employees
  • Gendered differences in impacts

Across all countries, the researchers have found that the 4-day week results in a significant increase in physical and mental health, life satisfaction, work-life balance, and work-family balance. They also saw an increase in average daily sleep hours, as well as fewer sleep problems, and less frequent anxiety and fatigue. They found improvements in job satisfaction alongside considerable reduction in burnout. Employees involved in the trial had more time to dedicate to personal care, social connections and hobbies. Environmental gains included reduced commuting and increases in pro-environmental behaviour in some circumstances.

I'm working more productively. I'm working much smarter. I have been more focused throughout the day.

— Brenda, Employee

Irish Trial team

  • Orla Kelly, Assistant Professor, UCD (Principal Investigator, Irish Trial)
  • Tatiana Benzdenezhnykh, Doctoral Student, UCD School of Economics (Research Assistant)

Global Trial team

  • Juliet Schor, Professor, Boston College (Lead Investigator)
  • Wen Fan, Associate Professor, Boston College (Co-Investigator)
  • Guolin Gu, Doctoral Student, Boston College (Research Assistant)
  • Orla Kelly, Assistant Professor, UCD (Co-Investigator)
  • Niamh Bridson Hubbard, Doctoral Student, Sociology, Cambridge University (Research Assistant)

Non-academic partners

  • Hazel Gavigan, Global Campaigns and Activation Officer, 4 Day Week Global
  • Dr Dale Whelehan, CEO, 4 Day Week Global
  • Joe O’Connor, Trial Coordinator, 4 Day Week Ireland


  • “The Triple Dividend? Assessing the Economic, Social and Environmental Impacts of Working Time Reduction in Ireland” is funded by Forsa.
  • The Boston College team is funded by the Hewitt Foundation.

Research impact

Health and social impact (for employees)

On average, employees involved in the trial report a significant increase in physical and mental health, life and relationship satisfaction, and work-family balance. Conversely, stress, burnout, fatigue and work-family conflict significantly declined. Levels of sleep deprivation have also fallen dramatically. In Ireland, women participants reported feeling more satisfied and secure in their jobs and experienced larger gains in sleep time and wellbeing, relative to male participants.

These are tangible, direct impacts for the 3,500 employees involved in the trial. If and when worktime reduction becomes more widespread, through the efforts of the researchers and other advocates (as described below), these benefits will be even more significant, potentially reaching millions.

Political impact (national)

As PI of the Irish trial, Dr Kelly has shared the project findings in various political contexts, advocating for the benefits of worktime reduction. For example, in May 2022 she held a briefing with Taoiseach Leo Varadkar and with the Minister for Public Expenditure and Reform on global trends in work reorganisation and worktime reduction in the public sector. She also presented the results of the Irish trial at an Oireachtas briefing in June 2023, and at the Irish Congress of Trade Unions Conference in July 2022 and 2023. Partly in response to the team’s research, delegates at the Association of Higher Civil and Public Servants annual conference backed motions instructing its executive committee to support campaigns for a four-day week.

Political impact (international)

The international team (of which UCD is part) have briefed policymakers on trial results, including Senators like Bernie Sanders (Vermont), and Mark Takano (California). Partly in response to the research, Senator Takano recently introduced a bill in February 2023 to reduce the standard workweek from 40 hours to 32. After a briefing from the global team, Senator Sanders wrote an opinion piece in the Guardian, directly citing the results of the research.

Cultural impact

The team have also engaged in widespread public and media engagement (like this Opinion piece by Dr Kelly), in Ireland and internationally, on how longer hours do not necessarily lead to better organisational outcomes, addressing overwork and burnout, particularly in the aftermath of COVID-19, and the potential of the 4-day week to increase wellbeing and improve environmental outcomes. For further examples, including articles in the Irish Times, the Guardian, BBC, Time Magazine and Wall Street Journal, see References below.

Economic impact

The research showed that worktime reduction not only benefits employees, but the companies as well. 90% of those involved in the international trial stated that they planned to continue after the initial 6-month trial. In Ireland, all 12 participating companies plan to continue with the four-day week schedule after the trial. Again, in time, more and more companies can expect to enjoy the benefits of worktime reduction.

In terms of productivity, we're beating every target from the previous year, hands down. So if anything, reducing our working week has improved priority productivity to a level that it would be a very foolish decision to go back to 5 days.

— Ann, Manager

Environmental impact

During the trial, the research team observed a decrease in commuting among employees and an increase across three forms of pro-environmental behaviour. In addition, many organisations decrease energy use by closing on a Friday.

Academic impact

Compared with much previous research on worktime reduction, which has mainly involved individual company case studies, Dr Kelly and the team are constructing a large database of employee and organisational outcomes across different countries and types of companies and organisations. They now have a dataset of more than 150 companies and more than 35,00 employees. They have published four widely-cited technical reports, and have several academic papers in the draft and review stages.

“Life has gotten so much better, just a much better balance like, Oh, my God! Like, I don't know how people who don't have it can function. Honestly, even now, when I look back on my own life, I'm like, how was I able to manage to do anything like? Especially when you work a full-on and intense job. [before the four-day week] I didn’t feel I had the time or capacity for all the other parts of my life that needed attention. Having that extra day is a game-changer!”
— Carol, Employee

“I'm working more productively. I'm working much smarter. I have been more focused throughout the day. I'm not getting to one o'clock and having a slump.”
— Brenda, Employee

 “It’s given me more time to spend with my family members, and I think that the even greater benefit has been that it frees up my mental space for when I’m interacting with them. The mental load of work doesn’t spill into your personal life.”
— Helen, Employee

“In terms of productivity, we're beating every target from the previous year, hands down. So if anything, reducing our working week has improved priority productivity to a level that it would be a very foolish decision to go back to 5 days.”
— Ann, Manager

“As a manager, my job has gotten easier because the reduced work time has motivated employees and increased morale. They know they could go back to five days if the arrangement stops working for the company. So, they work together to make sure that it does.”
— Brian, Manager

Additional quotes can be found in the project’s Irish report.

Technical reports

Selected TV coverage of the report

  • RTÉ Six One – 30 November 2022
  • RTÉ News: 9 O’clock – 5 May 2023
  • Ireland AM – 30 November 2022

Selected national news articles

Selected international news articles

Selected radio programs

Academic outputs

The research team is in the early stages of writing several academic papers. Two are under review, and one will be submitted by September 2023.

  • Fan, W., Schor, J., Kelly, O., & Gu, G. (2023, December 23). Does work time reduction improve workers' well-being? Evidence from global four-day workweek trials. DOI:
  • Kelly, O Schor, J. Fan, W.,, Gu, G, Bridson Hubbard N., Benzdenezhnykh , T. Does the 4-Day Week 4-day Week promote Gender Equality? (In draft)
  • Kelly, O Schor, J. Fan, W.,, Gu, G, Bridson Hubbard N., Benzdenezhnykh , T The 4-Day Week and Time Use; the Case of Ireland (in draft)