A causal tree is a structured probabilistic model that breaks down a complex event into a hierarchy of independent, verifiable sub-conditions. Each node has a probability, and the tree computes the overall probability of the root event.
A causal tree is how SimpleFunctions thinks about prediction markets. Instead of asking "what's the probability of X?" directly, we decompose the question into smaller, more answerable components.
A causal tree has:
- Root node: The ultimate question (e.g., "Will Iran-Israel conflict escalate to direct confrontation?")
- Branch nodes: Conditions that contribute to the root outcome
- Leaf nodes: Observable, verifiable facts that can be tracked
Root: Iran-Israel direct confrontation (p = 35%)
├── n1: Iran retaliates beyond proxies (p = 45%)
│ ├── n1.1: Missile/drone strike on Israeli territory (p = 60%)
│ └── n1.2: Naval confrontation in Strait of Hormuz (p = 30%)
├── n2: US military involvement (p = 25%)
│ ├── n2.1: US bases in region attacked (p = 40%)
│ └── n2.2: Congressional authorization (p = 15%)
└── n3: Diplomatic channels fail (p = 55%)
├── n3.1: UN Security Council deadlocked (p = 70%)
└── n3.2: Back-channel negotiations collapse (p = 45%)
- Decomposition makes estimation easier: Estimating "probability of WWIII" is impossible. Estimating "probability of UN Security Council deadlock on Iran resolution" is tractable.
- Information maps to nodes: A headline about Iranian missile tests maps directly to node n1.1. Without the tree, you'd have to reason about how it affects the overall probability — with the tree, you update one node and the math propagates.
- Confidence tracking: Each node has both a probability and a confidence level. If n3.2 has low confidence, you know where to focus research.
When the heartbeat service runs, it:
- Scans for new information (news, price changes)
- Maps each piece to a causal node
- Updates node probabilities
- Recomputes the root probability
- Compares against market prices to find edge
- Triggers strategy actions if conditions are met
sf thesis view --tree
Thesis: "US enters recession by end of 2026" Root probability: 42%
Causal tree: n1: Labor market deterioration p=55% conf=72% n1.1: Unemployment > 5% p=35% conf=68% n1.2: Non-farm payrolls < 100K/mo p=40% conf=65% n2: Consumer spending decline p=45% conf=70% n2.1: Real retail sales negative p=38% conf=75% n2.2: Consumer confidence < 80 p=52% conf=60% n3: Fed policy error p=30% conf=55% n3.1: Overtightening (rates > 5.5%) p=20% conf=50% n3.2: Too late to cut p=40% conf=58%
Root = weighted combination of branches Edge on KXRECSSNBER-26: 42% thesis - 28% market = +14pt
sf thesis view --treethesis, node-probability, confidence, thesis-implied-price, edge-detection