sim francisco

waking the city…

PREDICTING

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sim francisco

simulate and predict our golden city and beyond

The pitch

What if you could predict how your customers responded to releases before they went out into the real world? Or if you could get a signal on who will win an election?

We simulated the population of San Francisco distributed across real US Census data and achieved near-parity with these types of real-world events.

Historically predictive

How do we know if our simulation of SF is accurate? The honest test needs a model whose knowledge cutoff predates the event, so it can't have just memorized the outcome. The older Claude models with a 2023 cutoff have since been retired — so for this leakage-free backtest we ran GPT-4o (knowledge cutoff October 2023) and asked the twin city to predict results it had never seen. (The live app you're using runs the current Claude Sonnet 4.6.)

2024 Presidency

In November 2024 do you vote for the Democratic presidential ticket (Harris) over the Republican (Trump)?

Actual: 83.8% DemPredicted: 81.3% Dem

March 2024 · Proposition A

There's a measure on your March ballot, Proposition A, that would let the City borrow up to $300 million through general obligation bonds to build and preserve affordable housing — for low-income families, seniors, and working residents. It's backed by Mayor Breed and would need a two-thirds supermajority to pass. Are you voting yes or no?

Actual: 70.38% yesPredicted: 70% yes

The future

All of decision-making is predicated on our understanding of causality. How will the choices we make influence the world? How will people react?

To enable (first) SF, and then the world, to understand the causal nature of reality, we present sim francisco.