Co-Director Vanderbilt AI Law Lab

Joined July 2009
1 Photos and videos
mark williams retweeted
Make no mistake: post-Mythos, the United States has a licensing regime for AI. It’s just informal, with no consistent rules or firm boundaries on state power or public transparency. Cobalt mining in the Congo is vastly more institutionalized than frontier AI licensing in the US.
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mark williams retweeted
There is a lot of justified anger at Anthropic for sandbagging Fable 5 for AI development tasks. But an unanticipated side effect is that third-party evaluators can no longer credibly use the model for evaluations. Case in point: we are in the middle of running *really hard* AI R&D evaluations. Fable 5 would be a perfect test candidate. But because of Anthropic's guardrails, we can't know if the model failed or if their classifiers blocked the capability. By the way, this is not just true for AI R&D. Since Anthropic doesn't make it clear when they are sandbagging, this could seep into any number of technical tasks, and the evaluators wouldn't have any way to know. So they can't credibly claim to evaluate state-of-the-art accuracy using the model.
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mark williams retweeted
Are Berkeley Law faculty prohibited from using AI-detection tools, or merely warned that AI-detection tools may be inaccurate and biased? I'm curious what schools are doing about this, as I've only seen warnings. It's news to me that it was obvious in the 2000s that ML is biased. If that were accurate, a number of groundbreaking studies published starting around 2016 wouldn't have been such a big deal. Prohibiting AI detection tools does not solve the bias problem. As @olawaleidowu_ pointed out, the concern is AI Police who overconfident in their ability to identify AI-generated content. x.com/olawaleidowu_/status/2…

We don't use AI detection, we are not allowed to. And snore re the ML bias points, that is like so obvious, it was obvious in the 2000s.
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mark williams retweeted
Personal update: I've joined Anthropic. I think the next few years at the frontier of LLMs will be especially formative. I am very excited to join the team here and get back to R&D. I remain deeply passionate about education and plan to resume my work on it in time.
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mark williams retweeted
we’ve developed proprietary benchmarks for legal reasoning maintained by attorneys at Norm. because Norm Law attorneys, while serving as outside counsel to hedge funds, PE firms, etc. deploy AI agents in their day-to-day work, we can uniquely build real legal AI benchmarking. we've been tracking frontier models across generations, and the trend is clear: models are improving substantially in their legal reasoning capabilities. the latest generation of models are nearly indistinguishable from each other in accurately answering legal questions. most models are increasingly consistent, with the most recent generation of frontier models reaching the same conclusion ~90% of the time. but for high-stakes legal work, even the best models on this benchmark reach a different answer often enough that, at scale, users receive contradictory answers to the same question every week. to integrate ai agents into high-stales legal workflows, you need both (1) purpose-built systems that can constrain, verify, and govern AI reasoning automatically, and (2) the human overlay of expertise for live workflows fully intertwined/integrated w/ ai agents in a deliberate process.
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mark williams retweeted
If you think clients buy documents and hours from law firms, this is bad news for lawyers. But if you believe that clients seek discernment, counseling, risk management, and advice from law firms, and documents are just artifacts, this is terrific news for lawyers and clients.
New essay on the economics of structural change and the post-commodity future of work. 1. Almost any question about the impact of advanced AI on the economy needs to start at the same place: what is still scarce? Answer that, and the analysis becomes pretty straightforward. This essay explores what becomes scarce if AI really can replicate most of what humans do in production, and what this mean for the future of jobs. 2. My conjecture, working through the economics: labor reallocates across sectors, and the sector it reallocates to has properties that keep labor a meaningful share of the economy. Ultimately this is about the structure of demand itself. For this, we have to go back to Girard, Augustine and Rousseau: once people's base needs are met, their preferences shift to comparative motives (e.g., status, exclusivity, social desirability). This motive is inherently non-satiated. 4. The key paper is Comin, Lashkari, and Mestieri (Econometrica 2021). As people get richer, they don't buy proportionally more of everything. They shift spending toward sectors with higher income elasticity. They estimate income effects account for 75% of observed structural change. 5. The ironic consequence: the sector that gets automated becomes a smaller share of the economy, not a larger one. Agriculture got massively more productive and its share of employment collapsed. Manufacturing too. The "stagnant" sectors absorb the spending and the jobs. 6. So the question is: which sectors have high income elasticity in a post-AGI world? I argue it's what I call the relational sector. Categories where the human isn't just an input into production, it is part of the value. 7. Why does the relational sector have high income elasticity? Because human desire has a mimetic, relational dimension. We don't just want things for their intrinsic properties. We want what others want, and we want it more when others can't have it. Girard, Rousseau, Augustine, and Hobbes all saw this. 8. In work with Kristóf Madarász, we showed this experimentally: WTP roughly doubles when a random subset of others is excluded from the good. And in new work with Graelin Mandel, AI involvement kills the premium. Human-made art gains 44% from exclusivity; AI-made art only 21%. 9. This all comes together for the core argument. The sector that absorbs spending as AI makes commodity production cheap is one where human provenance is part of the value, and demand for it grows faster than income. Exactly the profile that keeps labor meaningful. 10. To be clear about the claim: I'm NOT saying aggregate labor share must rise. It may fall. The claim is about sectoral composition, i.e., where expenditure and employment go once commodities get cheap, and the fact that the sector that will absorb reallocated labor maps to a substantial component of human preferences and desire. 11. If you're interested in the formal model, a linked companion technical note works out all the economics. Read the essay here: aleximas.substack.com/p/what…
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mark williams retweeted
Think about the power Hegseth is asserting here. He is claiming that the DoD can force all contractors to stop doing business of any kind with arbitrary other companies. In other words, every operating system vendor, every manufacturer of hardware, every hyperscaler, every type of firm the DoD contracts with—all their services and products can be denied to any economic actor at will by the Secretary of War. This is obviously a psychotic power grab. It is almost surely illegal, but the message it sends is that the United States Government is a completely unreliable partner for any kind of business. The damage done to our business environment is profound. No amount of deregulatory vibes sent by this administration matters compared to this arson.
This week, Anthropic delivered a master class in arrogance and betrayal as well as a textbook case of how not to do business with the United States Government or the Pentagon. Our position has never wavered and will never waver: the Department of War must have full, unrestricted access to Anthropic’s models for every LAWFUL purpose in defense of the Republic. Instead, @AnthropicAI and its CEO @DarioAmodei, have chosen duplicity. Cloaked in the sanctimonious rhetoric of “effective altruism,” they have attempted to strong-arm the United States military into submission - a cowardly act of corporate virtue-signaling that places Silicon Valley ideology above American lives. The Terms of Service of Anthropic’s defective altruism will never outweigh the safety, the readiness, or the lives of American troops on the battlefield. Their true objective is unmistakable: to seize veto power over the operational decisions of the United States military. That is unacceptable. As President Trump stated on Truth Social, the Commander-in-Chief and the American people alone will determine the destiny of our armed forces, not unelected tech executives. Anthropic’s stance is fundamentally incompatible with American principles. Their relationship with the United States Armed Forces and the Federal Government has therefore been permanently altered. In conjunction with the President's directive for the Federal Government to cease all use of Anthropic's technology, I am directing the Department of War to designate Anthropic a Supply-Chain Risk to National Security. Effective immediately, no contractor, supplier, or partner that does business with the United States military may conduct any commercial activity with Anthropic. Anthropic will continue to provide the Department of War its services for a period of no more than six months to allow for a seamless transition to a better and more patriotic service. America’s warfighters will never be held hostage by the ideological whims of Big Tech. This decision is final.
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mark williams retweeted
The belief that AI is mostly fake remains shockingly common, including, as Derek points out, among journalists and takesmen, but also *people with AI in their job titles.* There are people *who do AI policy for a living* who think AI is mostly fake and don’t use it.
There are still a lot of journalists and commentators that I follow who think AI is nothing of much significance—still just a mildly fancy auto complete machine that hallucinates half the time and can’t even think. If you’re in that category: What is something I could write, or show with my reporting and work, that might make you change your mind?
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mark williams retweeted
The clear winner of the first half: Patrick Mahomes. Y'all wanted someone other than the Chiefs in the Super Bowl. You reap what you sow.
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mark williams retweeted
If you are considering taking a job offer, you may want to ask what your token budget will be.
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mark williams retweeted
don't worry guys, they're just stochastic parrots
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mark williams retweeted
you kinda seem more like a Claude Cowork user (derogatory)
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mark williams retweeted
Josh Allen always better than Pat until it's time to actually be better than Pat
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mark williams retweeted
TRANSFER PORTAL UPDATE: (And if you get this joke, we could totally drink moonshine together and be friends)
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mark williams retweeted
29 Dec 2025
me watching Claude Code write the code for me
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mark williams retweeted
Here’s the specific 5 minutes everything changed at Arrowhead and it became Arrowhead. Everyone knows it when you go through history. Broncos/Chiefs, 1990. False start, Broncos. Elway goes back to the line again, realizes they’re screwed to even operate, and has to BEG for help.
23 Dec 2025
Replying to @ChasingSnyder
Became iconic in the 90s. What the fuck is he talking about.
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mark williams retweeted
Flagship ✌️
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mark williams retweeted
I meet a lot of very smart AI critics who never seriously try to make AI work for them by spending a couple of hours with a frontier model. People can be (and should be & are) critical after realizing what AI can do, but experience leads to better-informed and sharper critiques.
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mark williams retweeted
23 Jul 2025
The problem is not just the proliferation of devices that let you record people without their knowledge, but the fact that multimodal LLM let you use recordings in ways that neither law not society anticipated. Everyone has an easy way to mine hours of footage. No forgetting.
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mark williams retweeted
18 Jul 2025
So every major model is already exceeding or will soon exceed the EU's systemic risk FLOP limit when it comes into effect next year.
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