Ethical behavior is not part of economic theory because it isn't the job of economists or business. It also "shouldn't" be their job. The purpose of government involvement in business is to regulate commerce, among other things like protect our safety and assure us of a shot at happiness.

It's all right there in Article 1: Section 8. We shouldn't need business to look out for its own ethics if our government did its job and defined the limit of how low business leaders can go instead of making it a contest. Not killing or maiming one's customers should be assumed, not a bonus feature. Only a strong government can make this happen.