The Global Rise of Four-Day Work Weeks: Evidence from Iceland, UK, and Japan

Over 200 companies globally have adopted four-day work weeks. Iceland's large-scale trial showed maintained or increased productivity. UK pilot found 56% of participants more productive. Japan's Microsoft trial saw 40% productivity boost. The 100-80-100 model: 100% pay for 80% time with 100% productivity expectation. Challenges include customer-facing roles, manufacturing shifts, and cultural resistance. Benefits include reduced burnout, lower turnover, and environmental impact from fewer commuting days.