In economics terms, that's the same thing. Tighter job market, more competition for dev talent, devs have more choices, the good ones choose the environment that values them the most.
Only in the most simplistic understanding – anyone serious will factor in limited information and human irrationality rather than assuming that observed market behaviour represents Econ 101 game-theoretical optimal decisions.
If you work at a large company, you might be well paid because you're working on the CEO's pet iOS project and there's a developer shortage. The market is working to give you higher pay but there's no relation to any sort of actual value. Most places don't even make a serious effort to quantify value or cost in a remotely scientific manner.
