Whether that increase in stability is wholly positive is arguable. In roaring economies, workers switch jobs more often, looking for higher pay or better bosses. The length of time spent at one job goes up in times of economic stress (such as the mid-aughts), when workers hang on for dear life. But whatever the cause, it’s clear that younger workers switch jobs less often than in the past. For women, also, the length of time at the average job has gone up markedly. (It’s now almost the same as for men.) To the extent that there was security in the past, it didn’t apply to women.