I don't know about started, it's been back and forth forever, but in recent history a big epochal change was the hostile takeover movement of the 80s. Many comp

I don't know about started, it's been back and forth forever, but in recent history a big epochal change was the hostile takeover movement of the 80s. Many companies, including those that had had a reputation for loyalty to their employees, were bought out by corporate raiders who often took actions that lead to huge number of layoffs.