It feels strange now to recall that two years ago we had just entered a three-month stretch of government-enforced hermithood after the first wave of Covid struck. Living alone, forbidden from spending time with anyone else, my social life consisted of Saturday nights in front of my laptop doing a virtual pub quiz. It quickly became the new normal, but now I wonder how I ever adjusted. One of the aspects of lockdown living I would like to reintroduce, though, is working less. As someone who is freelance for part of the week, for a while there was just less work available. And so, having written about the theory of the four-day week, I found myself living it in practice. Lucky enough to afford to take the hit, I discovered I loved having more time to myself – even though there wasn’t actually that much to do. It has made me a more enthusiastic proponent of shorter working hours. So I will watch with interest the results of the world’s largest four-day week pilot launched last week. The trial will involve 3,000 workers across 60 British companies, who will be paid the same salary for a shorter working week. The case for a four-day week starts with the insight that human progress should not just be measured by the accumulation of “stuff”, but rather of time. One hundred and fifty years ago, Britons worked on average a 62-hour week, an appalling thought. Who’s to say our current conception of full-time work, the five-day week, is right? As technology from the wheel to the widget means societies can produce more and more with the same human input, it seems a no-brainer to think that we should bank some of the gains by enriching our lives with more time spent with people we love on the things we enjoy, rather than more consumer goods. There are other benefits. Substituting more time over increases in collective wealth will also be better for the environment. And by embedding a more flexible working culture for both men and women, a shorter work week would help reduce the gender-based pay gap (much of which is accounted for by part-time work holding mothers back from progressing in workplaces where working full time is the norm). The concern, however, is that only some will get to benefit from these changes. Our labour market is riven not just by inequalities of pay but in working conditions, such as the amount of flexibility and autonomy employees are permitted. This was notable during the pandemic. While some of us got to work more flexibly from home, sometimes, admittedly, in less-than-ideal conditions, many others, especially those in lower-paid work, experienced little change in how they worked, having to put their health at risk to continue the daily grind. And now, as many white-collar companies embrace hybrid working, allowing their workers to cut down on commuting, others are stuck paying more for less frequent public transport or having to contend with the rising cost of petrol to get to and from work. The experience of technology has been different, too. Zoom may not be quite the same as sitting in a room with colleagues, but for me it has reduced time spent in unnecessary meetings. In contrast, some workers report they have experienced greater use of surveillance technology since the pandemic, which was already being deployed by companies such as Amazon, which uses it to track worker movements around the warehouse. Tools such as keystroke and phone call monitoring erode autonomy, privacy and trust between employer and employee. While 80% of us say we would like to reduce our working week, few are actually in a position to negotiate this with their employers without losing pay. Mass historical reductions in working time have been achieved as a result of collective union bargaining. But today, a fraction of employees are covered by collective bargaining agreements and the typical union member is a middle-income, professional public sector employee, with low-paid private sector workers out in the cold. It is also easy to see how the productivity argument, the idea that people working shorter weeks are more efficient and so can get almost as much done in less time, appeals more to white-collar employers than those in service sectors that depend on intensive human interaction, such as childcare and social care. So the danger is that better-off workers in a position to demand more from their employees will benefit from innovations in working time, while less affluent workers feel little benefit. That has happened in France, where, despite higher levels of unionisation, managers have disproportionately benefited from measures to reduce working time. The government, too, seems to be retreating from its manifesto commitment to make flexible working the default. It has picked cheap fights on flexible working as tabloid fodder, with ministers accusing civil servants working from home of laziness and seeming to back an it’s-not-work-if-you’re-not-at-your-desk culture. The difficulty is that working time improvements are no different to those in pay. They cost employers money and involve a redistribution of profits from owners to workers. The share of GDP that goes to workers in the form of wages is lower than it was at its peak in the 1970s and average working time hasn’t changed much since either. So the risk of this new trial is that it demonstrates that a move to a shorter working week isn’t cost-free and consequently gets ignored by most employers, save those who see this as a way of making themselves more competitive when it comes to recruitment and retention. The economic reality is that a shorter working week will never be delivered through the goodwill of employers. Just as it took the union movement to negotiate the significant reductions in working time that meant people were no longer expected to work on Saturdays, it will only happen in an economy where workers have more power to negotiate what’s good for them. Sonia Sodha is an Observer columnist