Nate Silver @NateSilver538
@jbarro I don't know. Low-ish density + can do everything outdoors in the summer? I'll grant you it's all pretty complicated. But if you're building a mental model, this is one of the important factors. We KNOW it matters to some degree (i.e. in an SIR model) and it COULD matter more. — PolitiTweet.org