From memory: last I heard the average is 18 months. I don’t know if that was accurate then or still is, nor how much it varies regionally or by any other criteria (I can look it up later but had a quick moment to reply and HN moves fast and might fill in the gap before I can take more time to look).

What is an acceptable duration for someone to stay at your outfit?

Plenty of career people at this consultancy. Also transplants. I just passed 5 years.

Consulting is a little unique in my experience - if there's a steady stream of work, you never really stick with the same client full time for the full 5 years. It's a lot easier to keep your skills fresh and move around to find interesting challenges

Does your employer offer its people the 10-20% annual salary increase so they do not have to look elsewhere for what the market is willing to provide? I ask this seriously.

No, that sounds a bit excessive.

If you're growing the business at a healthy clip, maybe those sorts of raises are sustainable.