Social Responsibility of Business

CEOs have responsibilities to the society in which they interact because they are members of said society before they are CEOs. Their responsibility is to truly maximize the value of the shareholders. That being the case, it would not be maximizing to create any negative externalities or direct produce any negative effects. Businesses only exist of the benefit of society, and as such are responsible for maximizing all the stakeholders interests too.

Labor Unions are not all the same, and not all good or bad. Labor Unions increase a dead weight loss for consumers, and tend to create monopolies. They make companies less efficient. Just treatment of workers is more important than efficiency, that said a Labor Union could be good. In practice, the effects are most probably more negative than positive. To an extent companies must seek efficiency and profits so as to maintain a labor force. As with all things a balance must be struck.