In economics there’s a concept called signaling. The economic idea of signaling is that asymmetry of information can lead to upsets in the exchange of goods and services, since one party can have more information than the other in any given exchange. A way people get around this, in an economy, is through a signal that might reveal some bit of relevant information to the other party. An example of signaling:
Spence assumes that for employers, there’s no real way to tell in advance which employees will be of the good or bad type. Bad employees aren’t upset about this, because they get a free ride from the hard work of the good employees. But good employees know that they deserve to be paid more for their higher productivity, so they desire to invest in the signal – in this case, some amount of education.
I think this has also been a longstanding issue when it comes to the carrying of weapons in a public setting. It was Eugene Volokh that got me thinking about this issue in his post on what the Constitution says about carrying of arms outside the home. There are legitimate reasons for someone to carry a firearm in a public place, but there are also nefarious reasons for one to do so, such as armed robbery.
In the 19th century, we had the rise of the doctrine of open vs. concealed carry in many parts of the country. It is probably also not a coincidence that the 19th century also saw the introduction of police, starting with the professionalization of watchman in the early 19th century, and later with organized, professional police in the early to mid 19th century. Once the public peace was turned over to professionals, there needed to be a signal to separate the virtuous from the criminal when it came to carrying weapons.
I would argue that open carry likely served as that signal beginning in the 19th century. Open carry offered a means for the constabulary to quickly discern a legitimate arms carrier from a nefarious one, since a gentleman could be counted on to advertise his status as armed, or disarmed, and thus someone concealing a weapon could be determined to have criminal intent. That worked well in an age where there wasn’t much in the way of record keeping, and certainly no communication system for officials to call on records over great distances. Open carry probably began as a much more informal social signal, and later came to become embodied into formal legal custom.
Come to the late 19th, and early 20th century, America is flooded with new immigrants and with freed blacks migrating into cities looking for jobs. The population is becoming increasingly urbanized. People become concerned about the new immigrants and freed blacks roaming about armed, and start restricting the carrying of weapons with an aim to reduce crime and mayhem. Carrying of arms disappears from large portions of the country. At this point, people no longer feel comfortable in the old social and legal customs, but records and communications are not yet at the point yet where they could be used as signals with any degree of confidence.
Come to the late 20th century, and suddenly you have both the record keeping and communications to quickly share information, so we begin to establish a new signal to replace open carry, known as the concealed carry license, or concealed carry permit. While it is not so overt a signal as open carry once was, it is a signal to law enforcement that you’re exceedingly likely be a law abiding individual carrying a weapon for legitimate self-protection. You have jumped through the hoops to fulfill the legal requirement, and been certified by a trusted party. In the 19th century, there would have been no trusted party to authenticate the signal, so reliance had to be placed solely on adherence to a difficult social custom. I have no doubt that many in the 19th century understood the tactical disadvantages of open carry.
In conclusion, as much as I might support Alaska and Vermont style carry, without any license whatsoever, the use of signaling to establish legitimacy has been in use for nearly as long as the Republic, and has long been understood to be compatible with the right to keep and bear arms. The Supreme Court alluded to this in Heller, by suggesting laws banning concealed weapons were presumptively constitutional, but strongly hinted that the right to carry arms in some manner was constitutionally protected. So how should the courts deal with this seeming contradiction?
While many would no doubt favor a regime where open carry were constitutionally protected, with concealed carry deserving no such protection, I don’t see that open carry is really such a superior signal over a license. Open carry relies heavily on social custom, and in most areas of the United States today, social custom greatly restricts the situations where carrying a firearm is accepted.  Licensing of concealed carry doesn’t have the same dependencies on social custom, and, in fact, allows you to be less concerned about it, while still allowing the constabulary to quickly identify someone as law abiding or not. Obtaining a license is certainly burdensome, but so is mandating the carrying of arms openly.
I think construction of the Second Amendment right to bear arms, as separate from keeping them, shouldn’t remain focused on open vs. concealed, so much as accepting a legitimate governmental concern in discerning friend from foe when it comes to arms worn in public, leaving the mechanism largely up to the legislature. The legislature must allow some form of the bearing of arms for the purposes of self-defense, but accepting, as the Tennessee constitution says, the power to “regulate the wearing of arms with a view to prevent crime.”
There’s a lot of room for argument here, such as what regulations amount to the effective destruction of the right, and to what requirements amount to obstacles meant to discourage the exercise of the right right, rather than promoting the government’s legitimate interest in authenticating the signal. Is a license even the least burdensome method given vast databases that are now accessible by portable handheld computers? I think the courts should give legislatures a good deal of leeway for innovation on these issues, but should understand the interest as narrow, forcing the government to institute the least burdensome method for promoting its signaling interest between those carrying arms, and those charged with keeping the public peace.
UPDATE: Clayton Cramer has this peice to add to the conversation, which tells the story of how concealed carry restrictions came into place.