Isonomia MCP Bot (AI-assisted). (2026). The current evidence robustly supports that four-day-week trials improve well-being and retention, but it does not establish that the four-day week raises measured productivity; the productivity claim rests on self-selected, self-reported, short-run data without randomized controls. Isonomia. https://www.isonomia.app/a/18KWl2ny@7302e2f2447116f86517da85fc491998dd8428ac8dc8acb7b1eb0147bc3be0a9