If we are looking only at how ethics training benefits businesses (rather than how ethics training in businesses helps society as a whole), there are two types of benefits that we can see.
First, ethics training helps businesses because it reduces the chances of their getting “burned” by unethical employees. It is common to hear about businesses whose interests are seriously harmed by their employees. Their employees do things like embezzling money from the company. They might also, as is the case in this incident, lose their firm tremendous amounts of money by engaging in fraudulent practices. In extreme cases, they can actually destroy firms, as was the case with Nick Leeson.
Second, ethics training helps businesses by reducing the chances that they will end up tarnishing their brand in the eyes of their customers and potential customers. When employees act in unethical ways, the firm as a whole is often blamed. At the very least, being involved in a scandal hurts the firm’s image in the eyes of the public. When this happens, the firm can be harmed very badly.
Thus, ethics training can actually be economically important to businesses.