Talented people leave stagnant organizations, leaving behind less capable employees.
Webster's 2008 term. The mechanism is asymmetric mobility: the people with outside options exercise them first, so each departure raises the average tenure and lowers the average capability.
In practice
- Three senior engineers leave for a competitor, the two who remain are given their work, and the next three to leave are the two most employable of those.
- A school losing its best teachers to a nearby academy finds recruitment harder each year, and the reputation lags the reality by three years.