Four-day work weeks increase productivity

What's this about?

People disagree about whether a four-day work week helps people get more work done.

The answer may change based on the job and how we measure “more.”

What supporters say

• Some work trials found that people kept up their work or got more done after losing one workday.
• Shorter weeks may cut tiredness, missed days, long talks, and other work that adds little value.
• Workers and bosses may plan better, set clear goals, and guard time for hard tasks.
• Better health, home life, and interest in work may help people do better over time.

What critics say

• People who joined these trials may differ from most workers, so the results may not fit every job.
• The firms in the trials may have chosen the plan, which could make the results look better.
• More work done in each hour does not mean more work gets done across the whole week.
• A firm may keep the same total work by asking people to work harder during fewer days.

How to read this

The number of points does not show which side is right; check how strong the proof is.

The bottom line

Shorter weeks look useful for some jobs, when teams change how they work.

Still, the proof does not show that four-day weeks raise total work for most jobs.

The claim that four-day work weeks increase productivity has gained support from workplace trials, but the evidence is not conclusive. The answer depends on whether productivity means output per hour or total output, and on the type of workplace adopting the shorter schedule.

The case for

A shorter week can improve efficiency when long hours create fatigue, absenteeism, unnecessary meetings and other low-value work. International labor research links very long working hours with lower hourly productivity and diminishing returns. In some workplaces, cutting hours may push managers and staff to set clearer priorities, reduce meetings and protect focused work. The potential benefit comes not simply from removing one workday, but from redesigning how work is done 1.

Several workplace trials have found that performance was maintained or improved after hours were reduced. A major UK pilot reported broadly stable revenue despite shorter working hours. Trials in Iceland’s public sector found that services were maintained or improved, while a New Zealand study by Perpetual Guardian found that performance was generally maintained. Microsoft Japan reported higher productivity per employee during its trial month. These results offer practical evidence that some organizations can shorten the week without losing performance (see Figure 2) 2.

The positive findings are most relevant to employers that actively reorganize work rather than simply close for an extra day. They also suggest that improvements in health, work-life balance and employee engagement could support productivity over time. However, those benefits are not themselves proof that measured output has increased: in the New Zealand study, for example, well-being improved while performance was generally maintained rather than clearly raised.

The case against

The strongest objection is that the major trials may not represent typical employers. Participation was often voluntary, companies chose to take part, and many were unusually motivated or capable of redesigning their operations. Several studies also lacked random assignment and relied partly on self-reported or company-selected measures. The results therefore show that a shorter week can work in selected workplaces, not that it will raise productivity across the economy 3.

A second problem is the difference between output per hour and total output. Workers may become more efficient during the hours they are present, yet the organization still has fewer total labor hours available. In some settings, efficiency gains can offset the lost time. In others, total production may remain unchanged or fall, especially when staffing, production schedules or services require continuous coverage (see Figure 4) 4.

The evidence may apply more readily to office-based or knowledge work than to manufacturing, retail, health care or round-the-clock operations. Work-time arrangements can affect manual and knowledge workers differently, and employers must consider staffing, customer coverage, pay and service continuity. Results from selected organizations should not be generalized without those qualifications.

The central evidence gap is not a lack of workplace observations. It is the difficulty of separating the effect of the four-day schedule from employer selection, simultaneous changes to work practices and differences in how performance was measured. Existing research includes studies from several countries, but it does not consistently compare total output using objective measures and randomized controls.

The bottom line

The evidence favors a conditional, not universal, version of the claim. Four-day work weeks can maintain or increase productivity in some well-suited organizations, particularly when shorter hours reduce fatigue and force better work design. But the evidence for a general productivity increase is only moderate and remains weaker than the evidence needed to establish a clear cause-and-effect relationship 12.

The opposing case is stronger on generalization: pilot participants may be unusually favorable cases, and higher productivity per hour may not compensate for fewer hours overall. The best conclusion is therefore that a four-day week is a workable productivity strategy for some employers—not a reliably productivity-boosting policy for all of them.