How steeply does hardship rise with schedule unpredictability?
As schedule unpredictability climbs, predicted material hardship climbs with it across four separate domains, and it does so after pay is accounted for.
Reviewed against primary sources on July 19, 2026 by the Soon operations research team
The evidence in one line
Moving from the most predictable to the most unpredictable schedules, the predicted probability that an hourly service worker reports hunger hardship rises from 23% to 50%, adjusting for wages, income, and hours (Schneider & Harknett, 2021). The same upward gradient appears in three other domains: residential, medical, and utility hardship. This is a cross-sectional survey, so it establishes association rather than cause, but the association is large and it survives controlling for pay.
Four kinds of hardship, one gradient
The survey behind this finding covers 37,263 hourly retail and food-service workers at 127 of the largest US firms, collected between 2017 and 2019. The sample skews the way the sector does: 73% female, mean age 33, median wage $11 per hour. Exposure is measured on a 4-point additive scale built from four employer practices: schedules posted with under two weeks notice, on-call shifts, shift cancellations, and last-minute timing changes. Each practice a worker is subject to moves that worker one step up the scale.
Across that scale, four separate hardship measures move in the same direction. Adjusting for wages, income, and hours, and moving from the most predictable to the most unpredictable schedules, the predicted probability of hunger hardship rises from 23% to 50%, residential hardship from 12% to 28%, medical hardship from 18% to 42%, and utility hardship from 24% to 44% (Schneider & Harknett, 2021). Any material hardship rises from about half to 70-75%.
What makes the pattern worth reporting is that the four domains draw on different budgets. Hunger, residential, medical, and utility hardship are recorded as distinct measures rather than folded into one headline index, and the gradient shows up in each of them. For base rates, across the full sample 30% report hunger hardship, 25% medical, and 31% utility.
The adjustment is what makes these numbers interesting
These figures are model-adjusted predicted probabilities, not counts. Read the 50% as what the model predicts for a worker at the top of the unpredictability scale once wages, income, and hours are held constant, never as the share of workers who experienced hunger hardship. That distinction is not pedantry, it is the entire reason the finding carries weight.
The obvious explanation for hardship among hourly service workers is low pay, and at a median wage of $11 per hour that explanation has real force. The gradient persists anyway. Whatever produces it is not accounted for by unpredictable schedules being concentrated among the lowest earners, because earnings and hours are already in the model. One reading consistent with that structure is that volatility, rather than level, is doing the work: income that swings week to week is hard to budget against, and a canceled shift lands as a hole in one month's rent rather than as a slightly lower annual figure.
What this survey can and cannot support
This is a cross-sectional survey on a non-probability sample. Workers were recruited rather than randomly sampled, and each respondent is observed once, so the design measures association and nothing stronger. Nothing here demonstrates that granting a worker two weeks notice would move that worker down the hardship gradient. That is a different claim, and it requires a different design. Holding wages, income, and hours constant strengthens the finding by removing the most obvious competing explanation, but adjustment is not identification: a control variable tells you what the gradient is not explained by, never which variable came first.
The defensible summary is that workers reporting more unpredictable schedules also report substantially more hardship, and that the association holds after pay and hours are accounted for. Treat this as evidence about the size and shape of a problem, not as a measured return on a scheduling change. The causal question, whether changing schedules changes outcomes, is what the randomized retail experiment covered separately in this library was built to answer, and that is where a business case should source its causal claim.
Why hardship reads as an operations problem
Hardship in these four domains does not live outside the schedule. The measures sit close to the mechanics of attendance. A worker under strain in the hunger, residential, medical, or utility domain is a worker whose ability to arrive on time and finish a shift is under strain too. Residential hardship in particular changes commute distance and transport reliability with no notice to the employer at all.
Be precise about what is inference here. The survey measures hardship. It does not measure attendance, turnover, or output, and it makes no claim about any of them. The step from hardship to reliability is an operational reading, not a result in this paper. Saying so plainly is what keeps the argument standing when a skeptical colleague opens the study.
The practical value of an additive exposure scale is that it names four things an operation already controls. Notice period, on-call practice, cancellations, and last-minute timing changes are separately countable in most scheduling systems, and most operations are worse at one of them than the others. Counting them per employee per month produces a local version of the study's exposure variable, which is a more useful management object than a generalized engagement score.
What this means for your schedule
- Build a local four-practice exposure count with one column each for notice under two weeks, on-call shifts, cancellations, and last-minute timing changes, so you can see where your own workers sit on the scale.
- Carry the caveat with the count: Schneider and Harknett (2021) is cross-sectional, so a worker high on your local scale is a worker at elevated risk, not a worker whose hardship your schedule has been shown to cause.
- Track the counts per employee per month rather than as a site average, because the gradient is about where an individual worker sits, not where a location averages out.
- Attack whichever of the four practices your own numbers show is worst, since an additive scale means removing any one of them moves a worker a step down it.
The business case
Among 37,263 hourly workers at 127 of the largest US firms, the predicted probability of any material hardship rises from about half to 70-75% across the range of schedule unpredictability, adjusting for wages, income, and hours (Schneider & Harknett, 2021). That is an association measured at one point in time, so present it as exposure sizing rather than as a proven effect.
That the gradient survives controlling for pay matters for budgeting: a raise and a stable schedule are not interchangeable levers, and treating them as substitutes assumes something this evidence does not show.
The four practices in the exposure scale are already countable in most scheduling systems, so this survey converts into a risk measure you can run against your own roster rather than a figure you have to take on trust.
Frequently asked questions
- Could the arrow run the other way, from hardship to bad schedules?
- Plausibly, and Schneider and Harknett (2021) cannot rule it out: 37,263 hourly workers were surveyed once, at a single point in time. The distinctive worry for this finding is selection. A worker already behind on rent or utility bills has less room to turn down an on-call shift, less leverage to push back on a last-minute change, and fewer options when choosing between employers, so arrears may route people into worse-scheduled jobs rather than result from them. Adjusting for wages, income, and hours does not settle this, because that adjustment removes pay as a competing explanation without establishing which variable came first.
- What counts as an unpredictable schedule here?
- In Schneider and Harknett (2021), exposure is a 4-point additive scale made of four employer practices: schedules posted with under two weeks notice, on-call shifts, shift cancellations, and last-minute changes to shift timing. A worker subject to more of these practices scores higher on the scale. The reported gradients, such as predicted hunger hardship running from 23% to 50%, compare the most predictable end of that scale to the most unpredictable end.
- Why does adjusting for wages, income, and hours matter so much?
- Because it rules out the most obvious alternative explanation. The 37,263 hourly workers in Schneider and Harknett (2021) earn a median wage of $11 per hour, so low pay could account for high hardship on its own. Holding pay, income, and hours constant in the model and still seeing predicted hunger hardship run from 23% to 50% means the gradient is not accounted for by unpredictable schedules landing on the lowest earners.
- How common is hardship among these workers overall?
- Across the full 37,263-worker sample in Schneider and Harknett (2021), 30% report hunger hardship, 25% report medical hardship, and 31% report utility hardship. Those base rates are useful context for the gradient: hardship is common throughout this workforce, and the finding is about how much more likely it becomes at the unpredictable end of the schedule scale, not about hardship appearing only there.
Sources
Every figure on this page is drawn from a cited primary source and checked against the original publication.
Schneider, D., & Harknett, K. (2021). Hard Times: Routine Schedule Unpredictability and Material Hardship among Service Sector Workers. Social Forces, 99(4), 1682โ1709. https://doi.org/10.1093/sf/soaa079
Cross-sectional survey (37,263 hourly workers at 127 large firms, 2017-2019, non-probability sample)
None of the studies cited here evaluated Soon.They examine scheduling practices, shift patterns, and working hours as studied by independent researchers, so their findings describe what those practices are associated with, not what any particular software produces.
This article summarizes published research for scheduling and operations decisions. It is not medical advice. Individual health questions belong with a qualified clinician.
Keep reading
What does a survey of 27,792 hourly workers say about unstable schedules and well-being?
The widest well-being gap in the data sits around canceled shifts, and the finding is correlational throughout.
Read →Does better scheduling actually pay?
One randomized experiment, two large surveys, and an honest account of how much of this field we could not verify.
Read →How Do You Judge a Scheduling Study?
A short field guide to reading scheduling research, worked through this library's own sources, including the claims we checked and cut.
Read →