My own theory:<p>For most employers, there's something almost inconceivable about rising salaries. It's been routine for so long to have layoffs, to tighten belts, to pull together in these tough times and sacrifice, that market power over labor has been internalized into the entire way they do business.<p>If you read any HR industry literature you'll see a lot about the costs of a bad hire and missing out on candidates because they were out of a company's budget. You will not see concern about the opportunity cost of leaving a position vacant. If a company spends six months hobbling along understaffed, waiting for the sure thing to walk in the door for $5k less, that will seriously harm their business. It isn't considered.<p>There are a lot of things like that, aspects of employment that the employer won't change because it simply isn't done. This sort of creates an informal price ceiling, which has exactly the effects you'd expect: lower supply (discouraged workers, low labor force participation), "shortages", and more or less frozen wages.