Jay Caspian Kang writes:

On March 10th, the day before Tom Hanks announced that he had tested positive for Covid-19, I drove my three-year-old daughter to her day care in Berkeley, California. The drive took us up College Avenue, where white-haired professors huddled at sidewalk café tables; we passed the fraternity houses where students gathered on the lawns. Just a few blocks from my daughter’s school, there’s a coffee shop with a clientele split equally between students and senior citizens. I sat there until noon, working on my laptop, before moving to one of the food courts frequented by international students from Asia; a few weeks later, many of them would be returning from winter trips home.

Roughly a hundred and twenty thousand people live in Berkeley—about twelve thousand per square mile. The city is about three times as dense as Houston, and roughly as crowded as Washington, D.C., Philadelphia, or Chicago. About fourteen per cent of its population counts as elderly; those seniors interact to an unusual degree with college students and travellers from Asia and Europe. Given all this, it was reasonable to guess in the early spring that Berkeley would soon be hit badly by the coronavirus. The same was true for San Francisco, which is just across the water from Berkeley and is the population center of the Bay Area, a nine-county region stretching from the farms and vineyards of Napa and Sonoma, in the north, to tech-centric San Mateo and Santa Clara Counties, in the south. San Francisco is a major tourist destination; the universities in the city and surrounding it are home to tens of thousands of international students, who crowd into classrooms and dormitories, swapping droplets. Tech workers often travel to and from San Francisco and its neighbors—Palo Alto, San Mateo—using the region’s heavily trafficked public-transportation system; they are served by hundreds of thousands of immigrants who live in multigenerational homes or unofficial workers’ dormitories. The wealth gap in the Bay Area has created an acute housing crisis, with thousands of destitute people living in tents and R.V.s, in temporary villages near or beneath city freeways. A viral spike in San Francisco, Berkeley, East Palo Alto, Oakland, or any of the other dense communities at the heart of the Bay Area seemed nearly unavoidable, and would have had disastrous consequences for the whole region.

We now know that some of the earliest coronavirus infections in the United States happened in Santa Clara County, home to Stanford University: the virus killed at least two county residents in February, well before the first official American death was recorded. And yet the bomb didn’t detonate. By January 1st, San Francisco, a city of almost a million people, had seen just a hundred and eighty-nine deaths. In Berkeley, only twelve residents had died. Although the region as a whole has struggled with the virus—during the current winter surge, many of its hospitals have come close to, or reached, their regular I.C.U. capacity—it has still done better than many parts of California, and better than much of the nation. Some eight million people live in the Bay Area; just more than twenty-six hundred have died of covid-19. Roughly the same number of people live in New York City, where, by the end of the year, there were more than twenty-five thousand deaths. In Los Angeles County, which is home to ten million people, four times as many have died as in the Bay Area. Even now, when the virus is less controlled and is spreading throughout urban, exurban, and rural communities, the number of cases in the densest Bay Area cities remains relatively low.

Credit for this outcome has tended to go to three groups of people: local officials, who acted with admirable synchrony and speed in issuing shelter-in-place orders; tech C.E.O.s, who were quick to move their businesses to all-remote operation; and the region’s citizens, who have, by and large, been willing and able to go along with restrictions. And yet their actions in themselves can’t wholly account for the relative success of the Bay Area’s response. “The narrative we like is that the citizens were all wonderful and informed and our leaders were all wonderful,” Bob Wachter, the chair of the Department of Medicine at the University of California, San Francisco, told me. “That might make us feel good, and part of that is absolutely true. But then you look anywhere else on the map, and you see places where they did something completely different and had a similar outcome—or you look somewhere that did pretty well and got overrun.” Boston, another college town with a highly educated population, shut down at roughly the same time as San Francisco. It also has a world-class health system, a smaller population, and less international traffic from Asia and Europe. Even so, it has experienced seven times as many deaths.

In trying to understand the pandemic, we gravitate toward general truths: if everyone wears masks and follows distancing protocols, viral spread will slow. That’s true; our practices matter. And yet the prevalence of the virus varies block by block, and some blocks are more vulnerable than others. To truly keep infections low, a pandemic response must find and help those people who are, for whatever reason, most likely to get infected. [Continue reading…]