# Joon Sung Park

Markdown copy of https://realalpha.app/people/joon-sung-park/ on Real Alpha, the best minutes from long interviews with the people building AI. Cite and link the page, not this copy.

Real Alpha has cut 8 moments of Joon Sung Park (Co-Founder & CEO, Simile) talking, from an interview on Sourcery published Oct 26, 2026.

- Role: Co-Founder & CEO, Simile

## What Joon Sung Park said

- [Simile tested digital twins against real people](https://realalpha.app/s/simile-tested-digital-twins-against-real-people/)
  Sourcery · Oct 26, 2026 · 2 min
  > “at the end of 2024, for the first time really in the field, we could actually show that we can predict people's behavior with 85% plus accuracy” — Joon Sung Park · [10:23](https://realalpha.app/v/-6Kg5N7JL7I/?t=623)
- [What people do can differ sharply from what they say](https://realalpha.app/s/what-people-do-can-differ-sharply-from-what-they-say/)
  Sourcery · Oct 26, 2026 · 2 min
  > “the activation energy for me to actually go to the gym is actually way higher than what I would expect.” — Joon Sung Park · [13:10](https://realalpha.app/v/-6Kg5N7JL7I/?t=790)
- [An EV message risked hurting the whole category](https://realalpha.app/s/an-ev-message-risked-hurting-the-whole-category/)
  Sourcery · Oct 26, 2026 · 2 min
  > “This particular messaging, this particular approach towards the market actually shifted people's overall perception of non-electric vehicle and globally actually lowered the sales more in that entire market.” — Joon Sung Park · [34:52](https://realalpha.app/v/-6Kg5N7JL7I/?t=2092)
- [Representative panels need sampling and consent safeguards](https://realalpha.app/s/representative-panels-need-sampling-and-consent-safeguards/)
  Sourcery · Oct 26, 2026 · 7 min
  > “So for us the no-goes are actually participants who cannot give informed consent.” — Joon Sung Park · [27:45](https://realalpha.app/v/-6Kg5N7JL7I/?t=1665)
- [Randomized tests show which levers can shift behavior](https://realalpha.app/s/randomized-tests-show-which-levers-can-shift-behavior/)
  Sourcery · Oct 26, 2026 · 3 min
  > “what really matters is actually the causal mechanism. It's the randomized control trials.” — Joon Sung Park · [43:46](https://realalpha.app/v/-6Kg5N7JL7I/?t=2626)
- [Simile can model a market, not just its customers](https://realalpha.app/s/simile-can-model-a-market-not-just-its-customers/)
  Sourcery · Oct 26, 2026 · 3 min
  > “sometimes hundreds of thousands of dollars, sometimes millions of dollars over many years, we can run them in simulation basically almost instantly.” — Joon Sung Park · [16:35](https://realalpha.app/v/-6Kg5N7JL7I/?t=995)
- [Smallville tested whether agents could form unscripted behavior](https://realalpha.app/s/smallville-tested-whether-agents-could-form-unscripted/)
  Sourcery · Oct 26, 2026 · 3 min
  > “none of this was pre-programmed, but what we could see is that we can basically create simulations of these people with emerging phenomena just coming out of the simulation.” — Joon Sung Park · [5:58](https://realalpha.app/v/-6Kg5N7JL7I/?t=358)
- [People choose based on the alternatives actually available](https://realalpha.app/s/people-choose-based-on-the-alternatives-actually-available/)
  Sourcery · Oct 26, 2026 · 2 min
  > “Optionality and the type of optionality often really governs people's behaviors.” — Joon Sung Park · [15:27](https://realalpha.app/v/-6Kg5N7JL7I/?t=927)

## The episode

- [The $2B AI Startup Simulating Human Behavior with 85% Accuracy](https://realalpha.app/v/-6Kg5N7JL7I/) · Sourcery · Oct 26, 2026