Joon Sung Park
Co-founder & CEO, Simile. On 3 shows, 2 appearances. The Shows tab opens the full record on each.
founderexecutivescientistacademic@joon_s_pk ↗LinkedIn ↗joonsungpark.com ↗
Joon Sung Park is the co-founder and CEO of Simile, an AI startup building behavioral foundation models. He is best known for his Stanford University research introducing Generative Agents, which demonstrated autonomous human social behavior simulation.
3shows
2appearances
67statements
10resolved
9supported
1contradicted
90%fully supported
2said about them ↓ Everything Joon Sung Park said on any show that made the record, most notable first. Each card names its show and opens the statement there.
Park: Training is required for new world physics, while prompting suffices for reactions
“My intuition behind the actual, when do you train or even post train a model versus just prompt a model is if the model has to learn the underlying physics of the world that it's operating in. So it has to learn new social physics. The places where it doesn't …”
Park: Public LLMs lack real human social physics due to web data bias
“I don't think the model has yet, at least the models that are out in the open, has yet learned the complete mapping of social physics of humanity. This actually is one of the core thesis of simile, right? And one of the core reason why that is the case is if y…”
Park: Generative agent digital twins replicate human behavior at 85% accuracy
“And this is where we basically could replicate people's behaviors and attitudes, 85% as accurately as people would replicate their own. So that actually was the first really paper that gave this validated results that we can actually model individuals in an ac…”
Park: Frontier models hit only 20-30% accuracy predicting niche human behavior
“Where in some cases, the model performance of frontier models go all the way down to 20, 30%. Especially if you go into that more niche population on topics that our customers will actually care about. On more gen pop, it might be around 50 to 60%.”
Park: Future simulations will cost as much to run as training models
“My hunch here is I do think in the next Some number of years, we will start creating simulations that will actually cost as much as training a foundation model.”
Park: Agent simulations beat multi-year field trials via instant repeated execution
“This is the reason why you want to run a simulation. You spend five years, forty million dollars on this one study and have one finding. But if you can run simulation many, many times instantly, then that's the value.”
Park: Simile Optimizes for Human Biases Over Super-Rationality
“So the way we see it is if you look at large length model companies today, fundamentally the task they have at hand is to create super rational, intelligent machines that are good at coding, that are good at natural sciences and mathematics. Similarly doesn't …”
Park: AI simulation can help solve wicked problems like climate change
“Simulation I do think can also be a cure for many of what we call quote unquote wicked problems.”
Park: Simulation models learn by validating daily real-world hypotheses
“I actually think simulation has even better mechanism, which is the world is our ground truth. We live in the ground truth world. So what we can do is every single day, we can be generating tens of thousands of hypotheses. Each hypothesis is mapped onto an end…”
Park: Simile models predict human behavior with 85% accuracy
“We show that we can actually predict people's behaviors and attitudes 85% as accurately as people replicate their own.”
Park: Synthetic panels will become larger than the human panel market
“The way I see it, synthetic panels will be larger than our, what we know to be the current human panel market, in part because this can really raise the ceiling of the kind of questions we can answer.”
Park: Within three years, single AI simulations will cost $20M
“I actually do think simulation can actually be the next frontier of that, where in my vision, I think there's a world in which in about two, three years, we're running a single simulation session, and that's going to take 10, twenty million dollars to run a si…”
Park: Accurate human simulation models must precede complex automation agents
“This technology around simulation, creating accurate representation of people ought to precede the more complex agents that would automate the world that we live in.”
Park: No true AI personal assistant exists today despite industry ambitions
“My hot take actually here though, is I don't think we've actually seen a true personal assistant that's actually useful in ways that actually meets the ambition of that particular line of work.”
Park: Advanced simulation discovers multi-step paths to achieve a target outcome
“So really what simulation allows you to do in its highest form is you give it not a problem or question, like what would people answer to the survey? That's not what we do. What we tell it is Here is a goal that we have. In the context of foundation, we want t…”
Park: Training on randomized controlled trials improves AI human-behavior prediction
“That by collecting a lot of these randomized control trials that are really well designed, we can make significant improvement in models capability to predict human behaviors.”
Park: Simile observes empirical scaling laws when modeling human behavior
“What we are seeing is at Simile, so we do post-train our own model. The thing that we're actually seeing is the early glimpse of scaling law in simulations. The more data about humans and more compute you ingest, you actually start to get predictive and predic…”
Park: A Nobel Prize in economics will be won from societal simulations
“And, you know, I also think, yes, I mean, I think there's a Nobel Prize to be won there, which wouldn't be surprising.”
Park: Stanford simulation first explicitly architected agent memory, planning, reflection
“And then was paired with memory planning and reflection. Really the first times that those concepts Came out to be an explicit part of the architecture in, quote unquote, agentic workflows.”
Park: Customers do not care about prediction unless trading stocks
“No one really cares about prediction. No one really cares about what's going to happen in the future unless you're trying to predict the stock market. What people actually care about is they want to shape the future.”
Park: Simile Replicated Multi-Month Consulting Studies in Two Minutes
“One of the ways we actually got some of our first customers was in the first call, They actually had a finding from, you know, large consulting companies, and they basically queried our system. Hey, if we were to rerun this, what would the system say? And we p…”
Park: PoC simulations are possible for anything; productionization is the real bottleneck
“I actually do think everything that we want to simulate, we can actually create the initial proof of concept. However, as we all know, one of the core challenges of AI is actually bridging the proof of concept with real value productionizable technology.”
Park: AI simulation can replace proxy representatives with direct societal modeling
“I actually don't think this is a limitation we have to suffer through in the future. I think there's a world in which we can truly create a layer that becomes a representation layer of our society and of our collective intelligence.”
The other half of the tape: Joon Sung Park's own voice is left out of every number here. Other people bring the name up 2 times in 2 episodes across the shows. every mention, with the transcript →
Who brings them up most Shawn Wang 1Jerry Liu 1
Every mention by year
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Latent Space 2
2026 1 mention in 1 episode
2023 1 mention in 1 episode
One line per show, most statements first. The link opens Joon's full record on that show: the calibration, argument clarity, speaking style and every statement made there.
| Show | Role there | Eps | Statements | Record | |
|---|---|---|---|---|---|
 20VCLEDGER | Co-founder & CEO, Simile | 1 | 40 | 80% 4/5 | full record on 20VC → |
| LATENT SPACELEDGER | Co-founder & CEO, Simile | 1 | 27 | 100% 3/3 | full record on Latent Space → |
 a16zLEDGER | Co-founder & CEO, Simile | 0 | 0 | 100% 2/2 | full record on the a16z Podcast → |