Elon Musk has gotten some well-deserved flack for predicting (in March) close to zero new infections in the U.S. by now.
Yet the focus on national or statewide infections has obscured a curious phenomenon: if he’d just predicted infections in Santa Clara county, he’d have been partly right – new cases peaked on April 10 at 83, were down to 23 on April 27, and appear to have dropped more since then (reporting may be incomplete for more recent days). (Santa Clara county roughly coincides with Silicon Valley; Tesla’s plants are a few miles from the Santa Clara county border, technically in Alameda county, but in most senses Tesla’s plants are part of Silicon Valley, which I’ll treat as a city, even though it’s more a city-less suburb).
Meanwhile, the statewide totals fail to show a trend of doing much more than stabilizing the rate of new cases. A good deal of that is due to Los Angeles.
What’s different between LA and Silicon Valley that would explain this difference?
It’s probably not much due to differences in government policy. California is using a mix of statewide rules and county rules, which makes it tricky to say whether there are policy differences. My impression is that most differences between county policies have relatively minor effects. I guessed that the most important difference would be in when they required facemasks use. Yet it looks like LA required facemasks on April 17, in synchrony with most of the bay area. But Santa Clara county differed by strongly urging, but not requiring, facemasks.
Maybe the reason that Santa Clara county didn’t create a formal facemask rule is that residents were sufficiently quick to adopt them that there was less need than in other counties? That fits my intuitions fairly well.
The LA area has been in the news for having crowded beaches. Outdoor activity in warm, sunny weather seems relatively low risk, but I doubt that the people on those beaches carefully evaluated the effects of ventilation, sun, and temperature on their risk, so it’s likely that the crowded beaches are at least a symptom of attitudes which cause the spread of infections.
I can see from Ohio that there are significant regional differences in people’s willingness to wear facemasks. I’m surprised that Ohio voters won’t put up with a rule to make them wear masks in order to enter stores. (Ohio’s Governor DeWine deserves much better constituents than he’s currently stuck with. Here in Berkeley, I get the impression that a majority decided that we needed to follow that rule before our government got around to announcing it).
Another relevant difference is that Silicon Valley workers switched to working from home more readily than most other places. This is likely a moderate factor, but I’d have expected a peak before April 10 if it explained more than half of Silicon Valley’s success.
Another influence might be blood types: type A blood creates higher risk of COVID-19, while type O lowers risk. Judging from the blood type differences between the U.S. and China, the large Chinese population in Silicon Valley ought to lower risk a bit.
LA’s apparently steady number of new cases can’t be very stable. People’s willingness to take precautions will decline at some point if herd immunity looks inevitable. Pushing in the other direction: increasing numbers of people will become immune, reducing the virus’ ability to spread. It seems almost impossible for these forces to balance out.
Robin Hanson sees a world polarized between regions that prevent infections and regions that get something like herd immunity. I expect that many regions, such as LA, will end up at various places in between, with maybe 10% of the population becoming immune. Since the people most likely get infected and to spread the virus will be over-represented in that fraction, it will put a sizable dent in R, enough to enable significant periods of suppression.
Robin expects that variance in R will be harmful. Zvi counters that variance is not bad, given sufficiently effective travel restrictions.
I mostly agree with Zvi here. The cost of restricting nearly all travel to commuting distance or less from home is much lower than the cost of the current drastic restrictions, so voters will typically demand a shift in that direction. My main concern is that these travel restrictions are getting lumped in with “lockdown measures” such as stay at home, and shut down “nonessential” businesses. That means that pressure to reopen activities that ought to be reopened could become pressure to remove most travel restrictions.
How many politicians will see beyond simple categories such as lockdowns versus reopening the economy, to pick and choose between the good and bad pieces of lockdowns? My impression is that at least half of the state and local politicians are on track to doing so, and have enough power to sidestep whatever problems exist at the federal level.
I sympathize with Musk’s desire to reopen Tesla plants, and it’s somewhat plausible that now is the right time for that. But I’m reluctant to side with him until he alters his tweets to be more narrowly targeted on specific, arguably safe, changes. I don’t want the world polarized between openers and closers.