Accounting statements can be manipulated. Please try to give an argument pro and con on this ethical issue. Any actual public examples you would like to cite would be most appreciated by all.

Scenario: A corporate executive wishes to make his financial numbers in order to get his bonus, receive his stock options and keep his job. To do this he reduces various accounting estimates such as bad debt expense. This makes the net income go up and he makes his numbers. He claims he truly believes his estimates are justified. Is this unethical? Explain.