Recent COVID-19 cases in Japan have shot up sharply, leading to another round of partial lockdowns, but reported cases appear subdued compared to the United States or Europe.
Total cases in the United States have surpassed 23,000,000 cumulative while the cumulative number for Japan passed 315,000 cases. That is 69 cases per 1,000 people in the United States compared with two cases per 1,000 in Japan. If Japan had the same ratio of cases per 1,000 people as the United States, Japan would have more than 8,700,000 cases. That approximates the population of metropolitan Tokyo.
If the United States had the same ratio of cases per 1,000 people as Japan, the number of cases would be under 660,000. That is about the population of Oklahoma City. Much has been researched and written about this disparity, but we will probably not learn of meaningful factors that can explain it for several more years.