[I don't think this segment needs updating although I am happy to be persuaded otherwise. Please feel free to contribute ideas for updating either in the body of the part or open them up for discussion on the discussion page.] The law has a good reason, then, to give me an exclusive right over my personal and real property. If it did not, I would have little reason to work to produce it. Or if I did work to produce it, I would then spend a great deal of my time trying to keep you away. It is better for everyone, the argument goes, if I have an exclusive right to my (rightly acquired) property, because then I have an incentive to produce it and not waste all my time trying to defend it.¹

Things are different with intellectual property. If you “take” my idea, I still have it. If I tell you an idea, you have not deprived me of it.² An unavoidable feature of intellectual property is that its consumption, as the economists like to put it, is “nonrivalrous.” Your consumption does not lessen mine. If I write a song, you can sing it without making it impossible for me to sing it. If I write a book, you can read a copy of it (please do) without disabling me from reading another copy of it. Ideas, at their core, can be shared with no reduction in the amount the “owner” can consume. This difference is fundamental, and it has been understood since the founding.

Jefferson put it better than I:

If nature has made any one thing less susceptible than all others of exclusive property, it is the action of the thinking power called an idea, which an individual may exclusively possess as long as he keeps it to himself; but the moment it is divulged, it forces itself into the possession of every one, and the receiver cannot dispossess himself of it. Its peculiar character, too, is that no one possesses the less, because every other possess the whole of it. He who receives an idea from me, receives instruction himself without lessening mine; as he who lites his taper at mine, receives light without darkening me. That ideas should freely spread from one to another over the globe, for the moral and mutual instruction of man, and improvement of his condition, seems to have been peculiarly and benevolently designed by nature, when she made them, like fire, expansible over all space, without lessening their density at any point, and like the air in which we breathe, move, and have our physical being, incapable of confinement or exclusive appropriation. Inventions then cannot, in nature, be a subject of property.³

Technically, Jefferson presents two concepts: one is the possibility of excluding others from using or getting access to an idea, which he defines as "action of the thinking power (...) which an individual may exclusively possess as long as he keeps it to himself". This is the question whether ideas are “excludable”; Jefferson affirms that an idea is "excludable" until "the moment it is divulged".

Before presenting the other concept, it is importante to notice that the divulging of an idea from one person to another depends on a medium (even the air is considered a medium, if you talk to other people) and a common language or code, between the transmitter and the receiver(s) to be shared.⁴

The other concept is whether my using of a divulged idea lessens your use of the same idea. This is the question of whether divulged ideas are “rivalrous”;⁵ again, Jefferson suggests that, once they are divulged, ideas are not “rivalrous”. Jefferson believes that the act of divulging/sharing has made ideas both nonexcludable and nonrivalrous, and that there is little that man can do to change this fact.⁶

In fact, shared ideas are both nonexcludable and nonrivalrous. I can exclude people from my secret ideas or writings — I can keep them secret, or build fences to keep people out. How easily, or how effectively, is a technical question. It depends on the architecture of protection that a given context provides. But given the proper technology, there is no doubt that I can keep people out. What I cannot do is to exclude people from my shared ideas or writings simply because they are not my secrets anymore, so (my ?) shared ideas are nonexcludable.

My shared ideas are “nonrivalrous” goods, too. No technology (that we know of) will erase an idea from your head as it passes into my head. No technology will make it so that I cannot share your ideas with no harm to you. My knowing what you know does not lessen your knowing of the same thing. That fact is given in the world, and it is that fact that makes intellectual property different. Unlike apples, and unlike houses, once shared, ideas are something I can take from you without diminishing what you have.

It does not follow, however, that there is no need for property rights over expressions or inventions.⁷ Just because you can have what I have without lessening what I have does not mean that the state has no reason to create rights over ideas, or over the expression of ideas.

If a novelist cannot stop you from copying (rather than buying) her book, then she has very little incentive to produce more books. She may have as much as she had before you took the work she produced, but if you take it without paying, she has no monetary incentive to produce more.

Now in fact, of course, the incentives an author faces are quite complex, and it is not possible to make simple generalizations about the incentives authors face.⁸ But generalizations do not have to be perfect to make a point: even if some authors write for free, it is still the case that the law needs some intellectual property rights. If the law did not protect authorship at all, there would be fewer authors. The law has a reason to protect the rights of authors, at least insofar as doing so gives them an incentive to produce.With ordinary property, the law must both create an incentive to produce and protect the right of possession; with intellectual property, the law need only create the incentive to produce.

Footnotes

¹ I am hiding a great deal of philosophy in this simplified utilitarian account, but for a powerful economic grounding of the point, see Harold Demsetz, “Toward a Theory of Property Rights,” American Economics Review 57 (1967): 347. Edit Delete

² For a wonderfully clear introduction to this point, as well as a complete analysis of the law, see Robert P. Merges et al., Intellectual Property in the New Technological Age (New York: Aspen Law and Business, 1997), ch. 1. Edit Delete

³ Thomas Jefferson, letter to Isaac Mcpherson, August 13, 1813, reprinted in Writings of Thomas Jefferson, 1790–1826, vol. 6, edited by H. A. Washington (1854), 180–81, quoted in Graham v John Deere Company, 383 US 1, 8–9 n.2 (1966). Edit Delete

⁴ For the classic discussion, see Kenneth J. Arrow, “Economic Welfare and the Allocation of Resources for Invention,” in The Rate and Direction of Inventive Activity: Economic and Social Factors (Princeton, N.J.: Princeton University Press, 1962), 609, 616–17. Edit Delete

⁵ For a powerfully compelling problematization of the economic perspective in this context, see Boyle, “Intellectual Property Policy Online,” 35–46. Boyle’s work evinces the indeterminacy that economics ought to profess about whether increasing property rights over information will also increase the production of information. Edit Delete

⁶ Some will insist on calling this “property”; see Frank H. Easterbrook, “Intellectual Property Is Still Property,” Harvard Journal of Law and Public Policy 13 (1990): 108. Edit Delete

⁷ This is the message of Justice Stephen Breyer’s work on copyright, for example, “The Uneasy Case for Copyright.” Edit Delete