need to solve the following problem

Some economists did a study of the market for economists in Britain.  They found that the quantity demanded was about 150 per year, and that the quantity supplied was about 300 per year.  (a) What did they predict would happen to economists' salaries, (b) What likely happens to the excess economists, and (c) Why doesn't the price change immediately to bring the quantity supplied and the quantity demanded into equilibrium?