Pilot schemes are generous environments. Everyone is being observed, everyone is motivated, and the results arrive before the novelty wears off.
The question worth asking is what happened after the researchers left. We contacted 63 organisations that completed a shortened-week trial and asked a single question: are you still doing it?
Forty-one said yes
The ones that kept it were not concentrated in any sector. They shared a structural feature instead: they had cut meetings before they cut hours. Firms that removed a day without removing anything else reverted within a year, almost without exception.
“We gave people back a day and left the calendar untouched,” one operations director said. “So they worked four days and answered messages on the fifth. That is not a four-day week, that is a pay cut in disguise.”