Employees That Stay In Companies Longer Get Paid Less

Very much this.

In London, certainly within Financial Tech, it is almost expected that you will job hop every few years, so the employers tend to price this in, with small incremental pay rises, little training, but often reasonable bonuses, to at least keep you there for about three years.

We also saw this was more prevalent with our offshore outsourced colleagues - over there anyone with even a modicum of skill would job hop every 6-18 months. Each time to lock in a payrise.

Employers will give you the shaft without a heartbeat of second thought; never seen why they should expect more from their "resources".

This is fascinating that there is actually hard evidence for this, but it's not surprising to me given my own experiences.

When I first started out as an "intermediate" software developer (after a couple years as doing contract work) I was poached twice within a year of taking a position, both times the offers were at least 30% higher, an amount my existing employers where highly unlikely to match (in fact in the second case I knew this because I had already attempted to negotiate a salary increase with them before leaving).

These were, as they say, offers I couldn't refuse. To financially cripple myself for the sake of loyalty would have been stupid. Moreover I felt it would also be stupid to remain with an organization that clearly had broken retention policies for employees.

What's somewhat surprising is that this occurred in Vancouver, a city that is notorious for low pay in the tech sector. Nowadays, if I wasn't doing my own startup I'm quite certain I would have received another offer of at least a 50% increase by now.

As a potential employer now I'm trying to figure out how best to ensure that I'm not making the same mistakes I saw at the places I worked for. Best as I can figure out, at least in Vancouver, this means paying salaries that exceed expectations and typical local numbers and look more like what people would be getting if they looked outside of Vancouver. I think this also means regular raises and bonuses so people don't feel like staying is going to hurt them financially.

Some companies have a limit on the number of times you can work for them, in order to prevent people from hopping and coming back for more money. I think a previous company I worked at had a limit of 2 employment periods, which they instituted (supposedly) after a large number of people took voluntary separation and then came back later after the company started growing more. The next time a voluntary separation came up the policy was implemented to prevent another round of that happening.

I feel like the ability to job hop like this will be in fairly small, concentrated geographic areas. In areas that aren't as concentrated it'll end up being pretty hard to do this.

For those of us in software development, an important thing to think about is what this does to code. The industry is full of old codebases tended by people who were never involved in the planning and initial design of those systems. Knowledge transfer rarely happens sufficiently to prevent accelerating maintenance headaches.

I think that we really need to find different ways of developing software to deal with this reality. A commenter here mentions the London financials community and people job hopping < 12-18 months. I've heard terrible horror stories about some of that code.