Therefore an employer should adopt a four-day week neither as a universal policy nor dismiss it outright, but should run a time-boxed, rever
Therefore an employer should adopt a four-day week neither as a universal policy nor dismiss it outright, but should run a time-boxed, reversible pilot - preceded by a workflow audit, scoped to redesign-amenable roles, and measured against objective output and quality metrics agreed in advance - treating it primarily as a retention-and-well-being investment whose output effect is, on current evidence, neutral rather than positive.
Because output stays stable only when the reduced hours are absorbed by redesigning work (cutting low-value meetings, admin, and interruptions) rather than by compressing the same tasks into fewer days, the four-day week's success is contingent on work redesign and on the job being redesign-amenable - and absent that redesign the 100-80-100 model becomes a hidden productivity trap.
A reversible, pre-registered pilot with objective metrics is the means that lets an employer verify the output-neutrality assumption for its own context before committing, converting an externally-biased evidence base into internally-valid evidence.
Employers value retention, recruitment, and reduced burnout-driven absenteeism, and the four-day week reliably delivers these (e.g. ~57% drop in turnover; 90%+ of trial companies continued the policy).
Scoping the pilot to redesign-amenable roles and auditing workflows first is necessary because the output-stability result does not transfer to coverage-bound or pace-limited work.