system
Given the following post, respond as if you're commenting on Reddit:
human
What cause labour shortage when employers can actually raise wage to atteact labour?

Does labour shortage in general really mean that the wage is set below the equalibrium? 
Then why the employers don't simply rasie the wage?
gpt
Yes, a labor shortage does mean the price of labor is too low. The answer to your question is that employers do raise wages, they just do so hesitantly and slowly. In a perfect classical economy, employers would also lower wages when labor becomes more abundant, but there is a  strong culture against cutting wages and salaries, at least in America. That's why companies usually lay people off in a downturn instead of cutting wages. Because they know they can't cut wages, employers are pretty hesitant to raise wages by a lot. The solution a lot of companies have come up with is a signing bonus, which is a way to pay people more now without promising to pay them more later (when, presumably, more people will have joined the labor market).