Will Personal Drones Require Further Development of Libertarian Property Theory?

Although drones are mostly now used by the military, that is going to change in the not too distant future. Both personal drones and commercial drones will become quite common. Indeed, some personal drones are already available.

This raises the question, how should drones, from a libertarian perspective, be treated relative to private property? Should, for example, one be allowed to fly a drone into a neighbor's backyard? If a neighbor is cooking outside on a grill, can I fly a drone directly above his shoulder and monitor his cooking? If someone is swimming in a swimming pool can I buzz a drone directly over that person's head? What about a drone flying 30,000 feet above a backyard, just like airplanes do?

I do not believe that there are any libertarian discussions that have completely resolved this matter. This post is an attempt to advance the discusion.

My focus on private drones was the result of an email sent to me by Daniel Reznicek. It consisted of one sentence:

I was wondering the libertarian perspective on the public at large using drones for personal use?

My initial response was three sentences:

Tricky question, the use of drones is fine above your own land. But libertarian air space might get a little complicated. For example, how high above someone else's property must a drone fly so that it is not to be considered an invasion of private property? I don't think the answer has been hashed out. 

I am going to forward this email to Walter Block to see if he has any thoughts on the subject.

Walter Block is, of course, a libertarian scholar who tends to do work, not exclusively, but occasionally on the fringes of libertarianism applications.  In other words, a perfect scholar to hurl the question at, and so I did. He replied:

 Dear  Bob, Dan: In my book on roads, see below, I wrestled with this issue. I did so because I oppose eminent domain, it ‘twas thought that this was necessary to address the holdout problem for a private highway developer. My view expressed in this book was that the private road developer could tunnel under the holdout’s land, or build a bridge over it, so he wouldn’t need eminent domain. Thus I reject the concept of  ad coelum, which means that the landowner also owns the ground under him, to the core of the earth, and the air above him, to the heavens above. This is incompatible with the Lockean-Rothbardian concept of homesteading (the land owner didn’t homestead territory 100 miles beneath the surface, so slant drilling is justified). He doesn’t own the air 40,000 feet above him, so he may not charge a fee to airplane firms. 

 Now to answer your question: people may fly airplanes above other people’s land, high up in the sky. But, drones are in effect airplanes filled with bombs. I regard drones, then, as a clear and present danger to others. So, even if ad coelum was correct, and someone did own the air above him, he’d have no more right to fly a bomb-laden drone in the air above all of us, any more than he would have a right to store dynamite, or an atom bomb, on his own property. On the latter see this: Block, Walter and Matthew Block. 2000. “Toward a Universal Libertarian Theory of Gun (Weapon) Control,” Ethics, Place and Environment, Vol. 3, No. 3, pp. 289-298; http://www.walterblock.com/publications/theory_gun_control.pdfhttp://www.walterblock.com/wp-content/uploads/publications/theory_gun_control.pdf

Now, Block here is to a great degree limiting the discussion to governemnt armed drones, and I concur with his view on armed drones. But I do not believe this answers the question with regard to personal and commercial unarmed drones.

I emailed Block again: 

Thanks for your quick reply. I am with you as far as weaponized drones. But what is your view on commercial drones and personal drones. I also get that there would be no problem with drones that are "high up in the sky," but I think the problem comes in with the commercial and personal drones, which are coming. The retailer Brookstone is already selling a personal drone. 

Will a neighbor be able to use a drone and fly it around me at shoulder level? OR will we just pick an arbitrary height where we say "above this airspace level" private property rights no longer exist?

Block replied this way, which suggests either boredom with the topic, boredom with me or a failure to understand my view that there is to date no satisfactory outline of how personal and commercial drones should be viewed from a libertarian perspective:

I answer all such questions by harking back to Lockean-Rothbardian homesteading theory. The way I see this, drones in the air will soon be followed by, Which ships have the right to use a river or ocean, as these amenities get more and more crowded. My answer: first come, first served. The people who first used these resources get a property right in them, that they can use or sell.

I agree that the question might be answered based on Lockean-Rothbardian homesteading theory and probably this is the best way to do so. But just how should such theory be applied? As Block states, a plane 40,000 feet above a homeowners backyard is not interfering with Lockean-Rothbardian homesteading private property rules. The  Lockean-Rothbardian homesteading view holds that a person must mix his labor with land to claim it as his property. Thus, a plane 40,000 feet above is not invading a person's backyard airspace, since the person has not mixed his labor with that altitude.

In his book, The Privatization of Roads and Highways  Block's answer is:

[...]if the landowner put in a three-story house, he also owns a “penumbra” of air above it, enough so as to enjoy the ordinary amenities of home ownership. This might be defined both in terms of height and number of flights of airplanes per day. The answer to the puzzle in this case would be in the thousands of feet.

But there is a problem with this view "to enjoy the ordinary amenities." Austrian economists know that enjoyment is subjective. When my son was young, I would take him to the airport and it was pretty cool to see planes just a few hundred feet above us. I'm sure if at the time, he had the option of living where planes flew low over him, he would have been in favor of it. He would have "enjoyed" it. People, in fact, do live close to airports because they like to see planes fly in close. (watch news reports after there is an incident with a plane at an airport, and you will hear from people who were out on their porches and balconies watching planes fly in and out). On the other hand, I'm sure others can be found who are annoyed at planes flying 30,000 feet above. In other words, there is no ordinary enjoyment. It is subjective. (Note, the problem of how high above a property a plane should be allowed to fly [or drone] is mostly a problem for those who are annoyed by drones or planes that fly even at very high altitudes. Since, it is no problem for those who enjoy drones flying at lower levels to grant permission for  planes and drones to enter their airspace)

So the question remains, how high must a drone stay above a person in his backyard? I suggest one answer might be that is it as high as the highest point of any structure on a person's property. If a person has a flag pole that is the highest point, then that person has mixed his labor to that altitude. If the highest point is a tree, then that person has mixed his labor to that altitude. If a person puts a huge tower (or pole) in his backyard, then he has mixed his labor to that altitude. It would be interesting to see what types of structures would be developed in a free market to keep drones at a non-menacing (to most) distance, if libertarian property rights would be recognized. But this mixture of property rights with airspace would likely only be comfortable not much beyond young boys and serious plane  (drone) fans. But still given subjective nature of enjoyment what is one to do? Some criteria must be developed.

An alternative view might be that a person mixes his labor relative to altitude by how far up a human eye can see, for example, a lit candle. A property owner lights a candle and thus, in a way mixes his labor, via the light from the candle with altitude.  According to Divio:

Under ideal conditions, the human eye can see a candle about three and a half miles out.

For a point source against a dark background, and with a fully dark-adapted human eye, the threshold for human visibility T (in footcandles) can be found by this equation:

ln T = .0828 [K ln(B)]^2 + .194[K ln(b)] - 9.73

... where B is the background brightness in nanoLamberts, and K = .4343. A perfectly dark, clear night sky will have a brightness of about 100 nanoLamberts, and this equation is valid only for backgrounds of 0.1 nanoLamberts or greater, which is essentially totally dark.

Solving this equation for T, the threshold visibility against a background of 0.1 nL gives us 5.3 x 10^-5 footcandles, which is the brightness of 1 candle at 18,792 feet, or 3.6 miles.

Allowing for atmospheric attenuation will reduce that number a bit.

Thus, using the candle measure, drones (and planes) would have to stay three and a half  miles (18,480 feet) above a backyard, unless permission to fly lower was granted by the property owner.

Note, I am fully aware that one could argue that for this "candle measure" it could be used for horizontal use as well as vertical use to capture unowned land. Thus, is this a strong enough "mixing" of labor with land (or altitude)? Should we limit the "candle measure" to altitude and not apply it to determination of horizontal land property rights? In some sense the measure we use for altitude will be arbitrary, though there would be a nice symmetry between using the Lockean-Rothbardian homesteading theory for determination of airspace property rights, but is the best alternative?

Certainly for vertical use, the "candle measure" has a certain attractiveness, since it would keep drones from buzzing immediately overhead, which would bother most of us, but probably not everyone in the world, and it seems to hold up fairly well to the Lockean-Rothbardian homesteading rule. I present this though as an opening discussion on a topic that will quickly have very practical applications as personal and commercial drones fly the skies.