The Laboratorium (3d ser.)

A blog by James Grimmelmann

Soyez réglé dans votre vie et ordinaire afin
d'être violent et original dans vos oeuvres.

Programming Property Law

One of the things that sent me to law school was finding a used copy of Jesse Dukeminier and James Krier’s casebook Property in a Seattle bookstore. It convinced me – at the time a professional programmer – that the actual, doctrinal study of law might be intellectually rewarding. (I wonder how my life might have turned out if I had picked up a less entertaining casebook.)

Although everything it was interesting, one section in particular stood out. Like every Property book, Dukeminier and Krier’s book devoted several central chapters to the intricate set of rules that govern how ownership of real estate can be divided up among different owners across time. If the owner of a parcel of land executes a deed transferring it “to Alice for life, and then to Bob and his heirs,” then Alice will have the right to enter on the land, live on it, grow crops, and so on for as long as she lives. At her death, automatically and without any need of action on anyone’s part, Alice’s rights will terminate and Bob will be entitled to enter on the land, live on it, grow crops, and so on. As Dukeminer and Krier patiently explain, Alice is said to have an interest called a “life estate” and Bob a “remainder.” There are more of these rules – many, many more of them – and they can be remarkably complicated, to the point that law students sometimes buy study aids to help them specifically with this part of the Property course.

There is something else striking about this system of “estates in land and future interests.” Other parts of the Property course are like most of law school; they involve the analogical process identifying factual similarities and differences between one case and another. But the doctrines of future interests are different. At least in the form that law students learn them, they are about the mechanical application of precise, interlocking rules. Other students find it notoriously frustrating. As a computer scientist, I found it fascinating. I loved all of law school, but I loved this part more than anything else. It was familiar.

The stylized language of conveyances like “to Alice for life, and then to Bob and his heirs” is a special kind of legal language – it is a programming language. The phrase “for life” is a keyword; the phrase “to Alice for life” is an expression. Each of them has a precise meaning. We can combine these expressions in specific, well-defined ways to build up larger expressions like “to Alice for life, then to Bob for life, then to Carol for life.” Centuries of judicial standardization have honed the rules of the system of future of estates; decades of legal education has given those rules clear and simple form.

In 2016, after I came to Cornell, I talked through some of these ideas with a creative and thoughtful computer-science graduate student, Shrutarshi Basu (currently faculty at Middlebury). If future interests were a programming language, we realized, we could define that language, such that “programs” like O conveys to Alice for life, then to Bob and his heirs. Alice dies. would have a well-defined meaning – in this case Bob owns a fee simple. We brought on board Basu’s advisor Nate Foster, who worked with us to nail down the formal semantics of this new programming language. Three more of Nate’s students – Anshuman Mohan, Shan Parikh, and Ryan Richardson – joined to help with programming the implementation.

I am happy to announce, that following six years of work, we have developed a new way of understanding future interests. We have defined a new programming language, which we call Orlando (for Orlando Bridgeman), that expresses the formalized language of Anglo-American real-property conveyances. And we have implemented that language in a system we call Littleton (for Thomas de Littleton of the Treatise on Tenures), a program that parses and analyzes property conveyances, translating them from stylized legal text like

O conveys Blackacre to A for life, then to B for life if B is married, then to C, but if D marries to D.

into simple graphs like

Then, if something else happens, such as

A dies.

Littleton updates the state of title, in this case to:

Littleton and Orlando model almost everything in the estates-in-land-and-future-interests portion of the first-year Property curriculum, including life estates, fees tail, terms of years, remainders and reversions, conditions subsequent and precedent, executory limitations and interests, class gifts, the Doctrine of Worthier Title and the Rule in Shelley’s case, merger, basic Rule Against Perpetuities problems, joint tenancies and tenancies in common, and the basics of wills and intestacy. They are no substitute for a trained and experienced lawyer, but they can do most of what we we expect law students to learn in their first course in the subject.

We have put a version of Littleton online, where anyone can use it. The Littleton interpreter includes a rich set of examples that anyone can modify and experiment with. It comes with includes a online textbook, Interactive Future Interests, that covers the standard elements of a Property curriculum. Property teachers and students can use it to explain, visualize, and explore the different kinds of conveyances and interests that first-year Property students learn. We hope that these tools will be useful for teaching and learning the rules that generations of law students have struggled with.

To enable others to build on our work and implement their own property-law tools, we have put online the Littleton source code and released it under an open-source license. Anyone can install it on their own computer or create their own online resources. And anyone can modify it to develop their own computerized interpretation of property law.

To share the lessons we have learned from developing Orlando and Littleton, we have published two articles describing them in detail. The first, Property Conveyances as a Programming Language, published in the conference proceedings of the Onward! programming-language symposium, is directed at computer scientists. It gives formal, mathematical semantics for the core of Orlando, and shows that it captures essential features of property law, such as nemo dat quot non habet. The second, A Programming Language for Future Interests, published in the Yale Journal of Law and Technology, is directed at legal scholars. It explains how Orlando and Littleton work, and describes the advantages of formalizing property law as a programming language. As we say in the conclusion:

To quote the computer scientist Donald Knuth, “Science is what we understand well enough to explain to a computer. Art is everything else we do.” For centuries, future interests have been an arcane art. Now they are a science.


Bo Burnham’s Inside reminds me of Helen DeWitt’s The Last Samurai and David Foster Wallace’s Oblivion: formally innovative, emotionally affecting, and obsessively inward-looking. While it is hard to tell where exactly the author stops and the character begins, they all could only have been created by someone struggling with profound depression.

Data Property

Christina Mulligan and I have a new paper, Data Property. Here’s the abstract:

In this, the Information Age, people and businesses depend on data. From your family photos to Google’s search index, data has become one of society’s most important resources. But there is a gaping hole in the law’s treatment of data. If someone destroys your car, that is the tort of conversion and the law gives a remedy. But if someone deletes your data, it is far from clear that they have done you a legally actionable wrong. If you are lucky, and the data was stored on your own computer, you may be able to sue them for trespass to a tangible chattel. But property law does not recognize the intangible data itself as a thing that can be impaired or converted, even though it is the data that you care about, and not the medium on which it is stored. It’s time to fix that.

This Article proposes, explains, and defends a system of property rights in data. On our theory, a person has possession of data when they control at least one copy of the data. A person who interferes with that possession can be liable, just as they can be liable for interference with possession of real property and tangible personal property. This treatment of data as an intangible thing that is instantiated in tangible copies coheres with the law’s treatment of information protected by intellectual property law. But importantly, it does not constitute an expansive new intellectual property right of the sort that scholars have warned against. Instead, a regime of data property fits comfortably into existing personal-property law, restoring a balanced and even treatment of the different kinds of things that matter for people’s lives and livelihoods.

The article is forthcoming in early 2023 in the American University Law Review. Comments welcome!

Reading Without Footprints

The phrase “I’m not going to link to it” has 385,000 results on Google. The idea is usually that the author wants to explain how someone is wrong on the Internet, but doesn’t want to reward that someone with pageviews, ad impressions, and other attention-based currencies. “Don’t feed the trolls,” goes the conventional wisdom, telling authors not to write about them. But in an age when silent analytics sentinels observe and report everything anyone does online, readers can feed the trolls without saying a word.

Actually, the problem is even worse. You can feed the trolls without ever interacting with them or their websites. If you Google “[person’s name] bad take,” you tell Google that [person’s name] is important right now. If you click on a search result, you reward a news site for writing an instant reaction story about the take. Every click teaches the Internet to supply more car crashes.

Not linking to the bad thing is usually described as a problem of trolls, and of social media, and of online discourse. But I think that it is also a problem of privacy. Reader privacy is well-recognized in law and in legal scholarship, and the threats it faces online are well-described. Not for nothing did Julie Cohen call for a right to read anonymously. Surveillance deters readers from seeking out unpopular opinions, facilitates uncannily manipulative advertising, and empowers the state to crush dissent.

To these I would add that attention can be a signal wrapped in an incentive. Sometimes, these signals and incentives are exactly what I want: I happily invite C.J. Sansom to shut up and take my money every time he publishes a new Shardlake book. But other times, I find myself uneasily worrying about how to find out a thing without causing there to be more of it in the world. There’s a weird new meme from an overrated TV show going around, and I want to know what actually happened in the scene. There’s a book out whose premise sounds awful, and I want to know if it’s as bad as I’ve been told. Or you-know-who just bleated out something typically terrible on his Twitter clone, and I don’t understand what all the people who are deliberately Not Linking To It are talking about.

We are losing the ability to read without consequences. There is something valuable about having a realm of contemplation that precedes the realm of action, a place to pause and gather one’s thoughts before committing. Leaving footprints everywhere you roam doesn’t just allow people to follow you. It also tramples paths, channeling humanity’s collective thoughts in ways they should perhaps not go.

The New Management

The blog has moved.

The last time it moved was in 2015. I had just taken a long break from Facebook and I liked remembering what it felt like to blog. As I write this seven years later, Eloi Morlock, mister iPod Submarine himself, may be just weeks away from becoming the unwilling and unqualified owner of Twitter. If and when that happens, I plan to take a long break from Twitter. Reconnecting with my blogging roots sounds like a good idea again.

But I’m also older, sadder, and wiser about something else: the mortality of all software. For as long as I have been blogging, I have been struggling with the problem of how to keep the blog going even as blogging platforms come and go. I started with a homebrew solution that involved hand-coding XML, running it through a stylesheet processor, and uploading the resulting HTML to a web server. It worked, if barely, but it was also beyond my capacity to maintain or extend. So after a couple of years of limping along (and an unfortunate experiment in turning the blog into a wiki), I threw in the towel and switched to Movable Type, which ran on my server and had a user-friendly web interface.

I used Movable Type for almost a decade. I thought that because it was open-source I would always be able to just keep on running it happily in my own corner. But Six Apart’s pivot to the enterprise market and paid subscription models left me stranded. The software worked, but without ongoing development support it became increasingly hard to deal with spam, security, and the endless accumulation of cruft.

In 2015, I moved over to Tumblr. In part I did it because I found a stunning Tumblr theme. And in part, I wanted the security and reliability of having a blog backed by a major Internet platform. It involved some significant sacrifices: I had to settle for static archives rather than importing all of my old posts. But at least I thought I achieved some measure of stability. Tumblr was a billion-dollar company, after all.

I’m going to pause now for those of you who know the corporate history to wipe the tears of laughter from your eyes. Suffice it to say that Tumblr is worth perhaps one percent of what Yahoo once paid for it, has an actively antagonistic userbase, and has stagnated technically since basically the day I started using it. So I have known for a while that my days there were numbered. Better to make an orderly exit at a time of my own choosing. The news about Twitter was just the final nudge to make me do something I had been planning for a while.

So this is all by way of saying that the Laboratorium is now powered by and I have never been happier with the technical setup. Jekyll runs on my own computer, from the command line, just like the good old first-generation XML scripts I wrote back at the turn of the century, when “blog” was still a neologism and the “blogosphere” was still a thing. It has an elegant template language that recalls everything that was good about Movable Type’s templates and nothing that was bad about them. It’s supported by an active and thriving open-source development community. And best of all, it stores every post in a simple and easy-to-parse text format. On that day when Jekyll too falls into ruin and decay, as is the inevitable fate of all software, I will be able to pack up my things again and move on.

This is something I have come to understand since the last iteration of this blog. Knowledge is not something that is created and then simply endures. It must be curated, transmitted, maintained. In every generation, you must retell the stories and transcribe the manuscripts. Copying my archives from server to server and from format to format is part of what keeps them alive.

Welcome to the Laboratorium, Third Series.