Time Was Never the Right Way to Measure Work. Here's Where That Idea Came From.

Madi Hanc, PhD

Aug 24

5 min read

Updated: Sep 1

Time-based pay, whether it's a lawyer's six-minute billing unit or a salaried employee's fixed 9-to-5, was never designed to measure the value of what someone produces. It was designed to make cost and effort visible to an employer or client, at a moment when there was no better proxy available. That proxy has always disadvantaged anyone without unlimited discretionary time, most consistently women carrying a disproportionate share of unpaid care. Is it time to rethink - or perhaps retire? - this model?

This is the first of a two-part series on time as the unit of work: this piece looks at where that idea came from and who it penalises; part two looks at how AI is breaking it entirely, and what the evidence says replaces it.

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Why did time become the unit of work in the first place?

Time-based pay in professional services traces to a specific, well-documented origin. In 1913, Reginald Heber Smith, newly graduated from Harvard Law School, took charge of the Boston Legal Aid Society and had to run roughly 2,000 cases a year on almost no budget. Working with Harvard Business School professor William Morse Cole, he applied Frederick Taylor's "scientific management" principles developed for manual labour (like bricklaying) to legal work: track time in six-minute units to see exactly where effort went. It only became the industry-wide default decades later, after a 1975 US Supreme Court ruling struck down fixed minimum fee schedules and firms needed a new, defensible way to price work (WilmerHale, 2010; Thomson Reuters Institute, 2025).

Salaried employment has a parallel history, and it's older than most people assume. Henry Ford established a five-day, 40-hour week across his factories in 1926 without cutting pay, explicitly demonstrating that 40 focused hours matched or beat 48 tired ones (Silicon Canals, 2026). But the same Taylorist "scientific management" thinking that produced the billable hour also produced the clocking-in machine: time, not output, became the unit management could see and standardise.

That created what organisational researchers call the "ideal worker norm": an assumption that a genuinely committed employee has no competing demands and demonstrates devotion through long, visible hours. The clearest evidence that this norm measures the wrong thing comes from organisational behaviour researcher Erin Reid's peer-reviewed study of 82 consultants at an elite global strategy firm. Some worked the expected 80-hour weeks. Others quietly worked 50 to 60 hours while producing equivalent client outcomes, and their performance reviews were indistinguishable from those working the "real" hours, because the firm had no way of measuring the difference beyond visible presence (Reid, 2015, HBR). The firm rewarded the appearance of time spent. It had no visibility into the value actually created.

Why does measuring time, instead of output, disadvantage women specifically?

Once presence or clocked time becomes the proxy for commitment, whoever has the least free time to convert into visible hours is read as less committed, and that is still overwhelmingly women.

This isn't just an observed pattern; it has a named economic mechanism. Nobel laureate economist Claudia Goldin's research on the "grand gender convergence" found that the remaining gender pay gap is now concentrated specifically in occupations with "nonlinear" pay: law, finance, and consulting, where working unbroken, specific, or excessive hours pays disproportionately more per hour than flexible or interrupted hours do.

It isn't that women are paid less for the same hour; it's that the pay structure itself rewards a pattern of availability that caregivers, disproportionately women, structurally cannot match (Goldin, 2014).

The underlying time gap behind this is large and global: women perform roughly three-quarters of unpaid care work, at 4 hours 25 minutes a day against men's 1 hour 23 minutes, a gap that narrows in OECD countries but persists (UNDP, 2024). Globally, 45% of working-age women are excluded from the labour market by unpaid care responsibilities, against 5% of men (UN Women, 2024).

Inside workplaces, this converts directly into a measurable penalty, and it isn't limited to law firms.

Flexibility stigma

A 2024 peer-reviewed study of 28 European countries (Chung & Seo, Social Indicators Research) found flexibility stigma against flexible and remote workers is still widespread, with the effect strongest for mothers of young children and women with other caring responsibilities, who were significantly more likely than childless women to believe flexible working would damage their careers (Chung & Seo, 2024).

Return-to-office resistance

Flexibility has a high priority for women, and last year’s waves of return-to-office (RTO) mandates put gender disparities once again in the spotlight. A 2025 UK study by Heejung Chung and Shiyu Yuan at King's Global Institute for Women's Leadership, analysing over 1 million Labour Force Survey observations and 50,000 responses from the Survey of Working Arrangements and Attitudes UK, found 58% of workers would now quit immediately or start job-hunting if forced into a full-time office return, up sharply from 2022. Women were far more likely to resist full RTO mandates than men, at 64% versus 51%.

Only 33% of mothers with young children said they would comply with a full-time mandate at all, evidence that rigid time-and-place measures of commitment are increasingly being rejected by exactly the workers who are most penalised by them (Chung & Yuan, 2025).

Financial and emotional costs of flexibility

These requirements for flexibility come at a cost. In law specifically, Major, Lindsey & Africa's (MLA) 2024 Partner Compensation Survey, based on responses from over 1,700 partners at AmLaw 200 firms, found male partners earned 29% more than female partners on average ($1.7 million vs $1.2 million), driven primarily by origination credit and billing-rate systems that favour uninterrupted availability (MLA, 2024).

In a world that rewards busyness, one solution is to fake it convincingly, but here, too, women seem to be at a disadvantage. A 2026 US survey of 1,003 full-time professionals found that among people who admit to "performing" busyness rather than working, women reported meaningfully more emotional cost than men: 22% felt guilty about it versus 14% of men, and 53% said it contributed to burnout versus 44% of men (Software Finder, 2026). This is strong evidence in its own right that when systems reward visible activity over output, the resulting performance is not gender-neutral in its cost.

So long, time-based pay?

The thread running through all of this is the same one: time was adopted as a proxy for commitment and productivity because it was easy to observe, not because it was accurate. As a result, the people with the least spare time to convert into visible hours have been paying for that inaccuracy ever since. With AI accelerating most work in an unprecedented way, will these outdated models continue to hold? And if not, what can replace them?

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This is part one of a two-part series. Part two looks at how AI is breaking time as the unit of measure for work from both directions, why professionals and salaried employees alike are quietly hiding productivity gains rather than being rewarded for them, and what the evidence says about outcome-based alternatives that actually work.