> But that's the very definition of insurance: spread the risk over the entire pool. But the devil is in the details, specifically in the definition of the "po

> But that's the very definition of insurance: spread the risk over the entire pool. But the devil is in the details, specifically in the definition of the "pool". To keep it fair (and subscription voluntary) generally requires pooling similar risk levels. Which is why for car insurance your driving record is important; for term life, your age and smoking status; etc. But at least in the US, health insurance is not really an insurance (as in your definition of spreading the risk of rare but expensive events); it is a complex monster touching negotiated pricing, access to care, etc.