Prompted a tightening of restrictions in beijing, here s cbs elizabeth palmer. shanghai s health authorities say more than half the population is no longer under lockdown but you would never know it. in practice most people are still not allowed to leave their compounds. though there has been a big push to get essential workers back on the job. among them agricultural staff on shanghai s outskirts. farmers getting back to their crops is one thing, factory workers is quite another. some of them have gone back to restarted plants but this video shows under a so called closed loop system where workers have to literally sleep on the job. china s lockdowns are causing labor shortages and brocken labor shortages and broken supply lines. and u.s. companies are warning they re likely to cost billions of dollars. that is why the covid outbreak in beijing has caused such alarm.