Automation and jobs: when technology boosts employment*
利用美国纺织、钢铁和汽车行业两个世纪的数据，发现自动化最初因需求高弹性而促进就业增长，但需求饱和后导致失业，说明技术可能要求工人向新行业转型。
SUMMARY Will new technologies cause industries to shed jobs, requiring novel policies to address mass unemployment? Sometimes productivity-enhancing technology increases industry employment instead. In manufacturing, jobs grew along with productivity for a century or more; only later did productivity gains bring declining employment. What changed? The elasticity of demand. Using data over two centuries for US textile, steel and auto industries, this paper shows that automation initially spurred job growth because demand was highly elastic. But demand later became satiated, leading to job losses. A simple model explains why this pattern might be common, suggesting that today’s technologies may cause some industries to decline and others to grow. Automation might not cause mass unemployment, but it may well require workers to make disruptive transitions to new industries, requiring new skills and occupations.