What has caused the slow rate of transmission in Japan?
It seems that the number of cases in Europe and the US keeps climbing (despite limited/late containment actions), but Japan seems to have it under control, comparatively speaking.
Many companies implemented work-from-home policies very quickly, almost all public events (sports, standardized tests) were canceled, schools and sports gyms closed, and some companies that didn't go to remote work had employees stagger commute times so trains would be less crowded. This all started, iirc, while the number of cases was still in the tens (not counting the cruise ship).
It is also more accepted to wear face masks, as many people have pollen allergies so it's quite normal, and there is less direct physical contact between people overall.
I remember reading that the number of flu cases was about half that of a normal flu season because of the precautions everyone was taking, which points to a high percentage of people doing their part to help prevent the spread.
This is the big difference: people doing their part to help instead of, say, panic-hoarding or obstreperously insisting on going on as if nothing were happening.
Culturally there is very little physical contact. Bowing instead of handshakes being the big one. No kisses on the cheek as greeting. In general, more refrain when it comes to touching. Also widespread mask use.
On the flip side though we have crowded public transport, and I've heard that people often brave it to work even if slightly sick.
Why do CDC and WHO discourage widespread mask usage? They suggest it only in a hospital setting or if caring for someone who has the virus. Is it because they are ineffective, or because they do not want to cause shortages?
Containment actions began less than a week ago in many european countries. It's expected the known cases grows unaffected for 7-10 days after containment comes into place.
The reason is that real cases start long before they become known cases.
Right, but even without testing, if the progression had followed what we've seen in Iran or Italy, there would be hundreds dying from Covid-19. This is not happening in Japan, and the virus has been in Japan much longer than those countries.
First detected case in Italy was January 31st, in Japan it was January 16th and/or 10th (quick Japanese and English Wikipedia check, correct me if you have a better source).
It seems that the number of cases in Europe and the US keeps climbing (despite limited/late containment actions), but Japan seems to have it under control, comparatively speaking.