Two businesses merge, now one bigger enterprise has two plants, which they consolidate into one. Maybe they outsource instead (or “globalize” if you prefer, tho

Two businesses merge, now one bigger enterprise has two plants, which they consolidate into one. Maybe they outsource instead (or “globalize” if you prefer, though I’m not clear on your distinction). Now one or two towns that previously had a business providing jobs don’t. Younger people leave since there is no opportunity there. Now repeat this for decades.