WASHINGTON – The country that gave the world the concept of a weekend is now hesitatingly auditioning a proposal for a four-day work week.

So many people are going to work exhausted physically and mentally that it is time to switch to allow for more leisure and relaxation, said Senator Bernie Sanders, chairman of the Senate Health, Education, Labour and Pensions Committee, as he introduced a Bill on March 14 to shrink the work week.

He proposed cutting it down, over four years, from 40 hours to 32 hours without loss of pay. Shifts longer than eight hours and weeks that go beyond 32 hours of work would be eligible for overtime pay.

“To suggest we have to maintain what we put in place 84 years ago (defining the work week) does not make a lot of sense,” he said, noting that the Senate last held a hearing on this subject in 1955.

“So I think maybe the time is now to renew that discussion.”

In the early 1930s, the Senate passed a Bill to establish a 30-hour work week, but it did not win support in the House of Representatives.

In 1938, then President Franklin Roosevelt signed the Fair Labour Standards Act and a 40-hour work week was established in 1940. It was an idea that eventually spread across the globe.

The Singapore civil service shifted in 2004 from a 5½-day to a five-day work week and gradually other employers also adopted that practice, allowing for a two-day weekend.

Data from the Manpower Ministry shows that actual hours worked per week by employees have fallen from 44.3 hours in 2022 to an average of 43.8 hours in 2023.

Mr Sanders’ logic for advancing shorter working hours rests on the finding that American workers are now more than 400 per cent more productive than they were when the 40-hour week was mandated.

They can take advantage of technology to work less, he argued. It was a fair outcome only, the progressive senator from Vermont said, pointing to the widening pay and wealth gap between the average worker and corporate chiefs.

A recent study cited by Mr Sanders found that 35 million workers in the United States – or 28 per cent of the total workforce – could have a four-day work week within a decade due to productivity gains led by artificial intelligence (AI), without loss in productivity or livelihoods.

Currently, the average full-time worker in the US works 42 hours a week, while 18 per cent of workers put in more than 60-hour weeks, and 40 per cent work at least 50 hours weekly.

“Despite these long hours, the average worker in America makes almost US$50 (S$67) a week less than he or she did 50 years ago after adjusting for inflation,” Mr Sanders said.

Bringing up global comparisons, he said employees in the US logged 204 more hours a year in 2022 than employees in Japan, 279 more hours than workers in Britain and 470 more hours than workers in Germany.

The US is no longer in the standard-setting role for work norms. France legislated a 35-hour work week in 2000 and is now weighing reducing it to 32 hours. Denmark and Norway are among other nations that have adopted a 37-hour work week, while Britain, Spain, Portugal and others have undertaken pilot studies.

Professor Juliet Schor, an economist and sociologist at Boston College, said her research had shown that shorter hours boosted productivity and reduced anxiety and fatigue.

She shared findings from a global study that she led on the four-day work week tried by more than 200 companies of diverse sizes and across service and manufacturing sectors.

Only 9 per cent of these companies chose to go back to a five-day schedule, she said, testifying before the Senate.

“If the US adopts a four-day, 32-hour week, it is likely that hourly productivity will rise. That has been the experience of both workers and management in our trials,” she said.

“Participants tell us that the new schedule is life-changing.”

But Professor Liberty Vittert, who teaches data science at Washington University’s Olin Business School in St Louis, said the data from studies could not be widely replicated.

The companies which sign up for these experiments have business models that are more easily adaptable to a shorter week, with the ability to cut out extraneous meetings and other “wasted” hours because they are mostly in white-collar industries, she added.

“Over 70 per cent of the US job economy is people working with their hands; they don’t necessarily have extraneous meetings or too many coffee breaks to cut out. So statistically, you can’t apply this type of cutting of hours across the entire economy,” Prof Vittert told lawmakers.

While Mr Sanders’ Bill has received the endorsement of several powerful trade unions including the American Federation of Labour and Congress of Industrial Organisations, United Auto Workers and Service Employees International Union, it has little chance of winning support from his Republican counterparts in the Senate.

Forceful objection came from Senator Bill Cassidy, a Republican from Louisiana, who pointed out that since there were almost nine million unfilled job openings in the US, the situation would worsen if the government were to mandate a 32-hour work week.

He said it would penalise employers who would be forced to either ship jobs overseas or dramatically increase prices to try to stay afloat. It would also, he said, threaten the millions of small businesses already operating on razor-thin margins, in part because they are unable to find enough workers.

“Employers would be forced to eliminate full-time positions in favour of part-time ones,” Mr Cassidy added.

When Japan shortened its work week from 46 to 30 hours between 1988 and 1996, economic output plummeted 20 per cent, he pointed out.

“A mom-and-pop restaurant is not seeing increased productivity from AI. They are having enough trouble finding enough employees to fill shifts. How is forcing them to provide a 32-hour work week at the same 40-hour pay going to turn out for them?” he asked.

“Hospital staffing shortages are already threatening public health. Why pass a law exacerbating those shortages?”

Dr Cindy Gordon, chief executive and AI ethicist at Toronto-based Saleschoice, a firm providing AI and advanced data science solutions, told The Straits Times that shorter working hours were a matter of time.

AI is a major productivity booster to all industries where tasks are highly routine, repetitive or dangerous in nature, she said.

In such industries, ratios of man-machine interfaces will drastically shift from 80 per cent human and 20 per cent machine to the inverse, she added.

Workers will flock to new positions such as architects, builders, ethicists and cyber security controllers in the evolving AI economy to design and support the industry shifts, Dr Gordon suggested.

Transitioning to a 32-hour work week made sense as this scenario plays out, she said.

“Eventually, even this outlook, proposed by the US Senate Bill, will shift to 16 hours a week in less than 10 years.”