My friend and mentor Michael Dooley's casebook on corporate law makes a better treatise than a teaching tool and I recommend that all corporate law professors track down a copy. In it, he mentioned in passing that the real policy problem with insider trading is that it is undisclosed executive compensation. Proving that great minds run in the same circles, Robert Miller has independently reached the same conclusion and authored a very interesting paper:
Accepting Epstein’s argument that firms wishing to allow their employees to insider trade should be permitted to do so, this article shows that there is still a crucial role for government in regulating insider trading. In particular, allowing employees to profit by insider trading is a form of employee compensation that, in contradistinction from conventional forms of equity compensation, results in unknowable and effectively unlimited costs to the company. Since providing employee compensation in this form causes the company to lose control of its compensation expense, even if insider trading were legal, virtually every company would rely on conventional forms of employee compensation and prohibit its employees from insider trading. But, pace Epstein, companies lack the means to detect insider trading by their employees, and even when they do catch employees insider trading, companies can impose only mild contractual sanctions, generally not exceeding disgorgement of profits and dismissal. As a result, although an efficient agreement between a company and its employee would prohibit the employee from insider trading, this prohibition cannot be effectively enforced by the company. Government, with its usual law enforcement powers, is better able to detect insider trading and can impose more severe sanctions on violators, including criminal penalties. Government should thus enforce a ban on insider trading in those instances, which will be virtually all instances, in which a company prohibits its employees from insider trading. The efficient solution is thus a hybrid system of private prohibition and public enforcement. Such a system is not unusual but the norm. Employers prohibit employees from embezzling their money and stealing their property, and employees are subject to contractual sanctions and dismissal for violating these prohibitions, but we still need statutes against theft to generate an optimal level of deterrence. This is all the more true when the employee misappropriates information, which is much harder to detect than a theft of money or property.
Miller, Robert T., Insider Trading and the Public Enforcement of Private Prohibitions: Some Complications in Enforcing Simple Rules for a Complex World (January 12, 2021). Available at SSRN: https://ssrn.com/abstract=3764835 or http://dx.doi.org/10.2139/ssrn.3764835
