Almost a decade ago, Professor Orin Kerr wrote a brilliant article called “An Equilibrium-Adjustment Theory of the Fourth Amendment.” In it, he posited a theory of the Fourth Amendment that describes judges applying Fourth Amendment doctrine so as to maintain some equilibrium between police power and personal liberty. As he writes:
When changing technology or social practice makes evidence substantially harder for the government to obtain, the Supreme Court generally adopts lower Fourth Amendment protections for these new circumstances to help restore the status quo ante level of government power. On the other hand, when changing technology or social practice makes evidence substantially easier for the government to obtain, the Supreme Court often embraces higher protections to help restore the prior level of privacy protection.
Kerr uses the thought experiment of a “Year Zero,” without technology (no fences, no cars, no cell phones, no wiretaps) in which the power of the state and the protection of privacy, specified by certain rules (warrants for homes; probable cause for a detention) are in equilibrium. (Kerr does not insist this equilibrium is ideal – it could empower police too much; it could protect privacy too much – the idea is simply that there’s an equilibrium.) As new technologies become available (criminals obtain cars; police obtain drug-sniffing dogs) the courts in a case by case fashion attempt to maintain the balance set at Year Zero.
It’s always struck me that Kerr’s analysis holds some promise for analyzing Second Amendment problems. Like the Fourth Amendment, the Second Amendment could operate from a Year Zero equilibrium (or multiple equilibria) between government power to possess and use implements of violence and private power to do the same. And, like the Fourth Amendment, Second Amendment doctrine must contend with both technological change (more deadly and concealable arms; micro-stamping) and social change (more social acceptance of concealed carry; more sensitive places) – changes that potentially upset whatever the Year Zero balance of gun rights and regulation may have been.
Of course, in some ways Second Amendment equilibria are even more complicated. Kerr focused on just one dynamic: police power and individual privacy. But with the Second Amendment there’s potentially numerous Year Zero equilibria: criminals and individuals; criminals and law enforcement; law enforcement and individuals; criminals and the military; military and individuals. Plus, there’s a set of considerations that may fundamentally shift the equilibria (Year Zero may not contemplate a standing army, for instance, or nuclear weapons). And finally, nothing in equilibrium adjustment theory requires the Year Zero equilibria to be socially optimal or morally acceptable. Indeed, arguing about the Year Zero equilibria – whether it’s tied to a set of institutional arrangements in 1791 – and whether it’s shifted – is the whole stuff of modern Second Amendment litigation.
That said, equilibrium adjustment theory does promise some purchase on the nature of the problem in Second Amendment adjudication and provides a vocabulary for the objective the doctrine attempts to achieve.