The biggest one-day changes in any company's stock price seem to happen when they post quarterly results.

If the results beat expectations then the stock price will go up, and if they do not then the stock price basically goes down very very drastically.

Since all these analysts have put the expected EPS out there for everyone to see -- including a company's board of directors -- why doesn't the board

(a) release quarterly results that are expectation-friendly, or

(b) if they know they are going to miss the results, then tell analysts to revise their expectations so there are no huge surprises on the day of results?