People act unethically for a number of reasons. Unethical behavior is defined as behavior that contravenes rules designed to maintain the fairness and morality of a situation. An example of unethical behavior is a representative of a company taking kickbacks from a salesman for preferential treatment. Behavior like this is motivated by various things.
One of the main causes of unethical behavior is greed. A person often chooses to act immorally or unethically for personal financial gain. In business, there are a number of opportunities for employees and employers to do the wrong thing. For example, an employee who has contact with a client may be willing to give them a discount in exchange for a kickback. An employer may have an opportunity to sell the company's stock when he has inside information about a drop in profit.
Sometimes, a person acts unethically in business because his employer condones the behavior. For example, in the late 1990s, traders at Enron conducted trades that cost the state of California millions of dollars in electricity payments. This was unethical, but the behavior was so common on the trading floor that it was never questioned.
A person acts unethically because she believes it helps her career. An unethical act is used as a means of impressing a superior or hurting the career of a competitor. For example, a person sabotages a co-worker's project as a means of making herself look better in comparison.
Ethical conflicts or violations are not always transparent, and it's easy for an employee to perform an unethical act without knowing it. For this reason, it is important for companies to make employees aware both of the company's general ethics policy, and specific examples of ethical and unethical behavior.