[midoridensha]

Salaries are a function of supply and demand. There's a huge amount of demand for these skills, and a new graduating class doesn't change that significantly (new grads aren't very productive after all, and salaries don't change that fast, since people don't change jobs every month). And demand has been increasing, faster than the new supply.

But there's probably other variables too. Why are tech salaries so low in Canada, for instance, despite there being lots of demand, and not that much supply (with many Canadians trying to go south to get the higher salaries there)?