正解: CCorrect: C
週4日制の成否は業務再設計と測定にかかっています。棚卸し→パイロット→測定→判断という手順が、成功事例に共通する方法です。Success with a four-day week hinges on redesigning work and measuring outcomes. The sequence of audit, pilot, measure, then decide is common to the successful cases.
2022年以降、英国、アイスランド、米国、オーストラリア等で行われた大規模な週4日制の試験（4 Day Week Global などが主導）は、多くの参加企業で売上維持と離職率低下、従業員の燃え尽き軽減を報告しました。ただし、成功の条件は「100-80-100モデル（給与100%、時間80%、成果100%）」を支える業務の再設計にあり、会議の削減、集中時間の確保、非同期化などを伴わない導入は失敗しやすいことも示されています。楽観シナリオではAIによる生産性向上が労働時間短縮を広く可能にし、ベースシナリオでは職種や業界で導入に差が生じ、悲観シナリオでは短縮分の仕事が圧縮され強度が上がるだけになります。選択肢Aは無検証の模倣、Bは根拠のない断定、Dは「給与維持」という制度の核心を外しています。どのシナリオでも、「時間ではなく成果で仕事を設計・評価する能力」は個人にも組織にも有効な備えです。Since 2022, large four-day week trials in the UK, Iceland, the US, Australia, and elsewhere, many led by 4 Day Week Global, have reported maintained revenue, lower attrition, and reduced burnout at many participating companies. The condition for success, however, is redesigning work to support the 100-80-100 model (100 percent pay, 80 percent time, 100 percent output), and adoption without cutting meetings, protecting focus time, and shifting to asynchronous work tends to fail. In an optimistic scenario, AI-driven productivity makes shorter hours widely feasible; in the baseline, adoption varies by occupation and industry; in the pessimistic scenario, work is merely compressed and intensity rises. Choice A is unexamined imitation, B is an unsupported assertion, and D removes the pay-maintenance core of the model. In any scenario, the ability to design and evaluate work by results rather than hours is a valuable preparation for individuals and organizations alike.
週4日制は、顧客対応が連続的に必要な業務や、シフト制の現場、医療・物流などでは設計が難しく、職種間の不公平感を生む恐れがあります。また、パイロット期間は参加者の意欲が高まる「ホーソン効果」が働き、長期的な効果を過大評価する可能性があります。A four-day week is hard to design for roles requiring continuous customer coverage, shift-based operations, and sectors such as healthcare and logistics, and it can create perceptions of unfairness between roles. Pilot periods may also inflate results through the Hawthorne effect, as participant motivation rises temporarily.
全社一律ではなく、職種ごとに「時間短縮」「シフトの交代制」「柔軟な休暇」など複数の形を用意し、公平性を担保しましょう。パイロットは最低6か月とし、対照群を置いて売上・品質・顧客満足・健康指標を比較することで、ホーソン効果を割り引いた判断が可能になります。Instead of a uniform rollout, offer several forms by role, such as reduced hours, rotating shifts, or flexible leave, to preserve fairness. Run pilots for at least six months with a control group and compare revenue, quality, customer satisfaction, and health indicators, which allows a judgment that discounts the Hawthorne effect.