There seems to be a second virus in the west: DMTMW - dont mention the M word - M like mask. Purely looking at the data, the doubling of the infection rate in western countries is between 2-3 days.

Looking at Asian countries:

Japan: 8-9 days - many people wearing masks

Thailand: 10+days - most people wearing masks

China: negative values - all people wearing masks (not just in Wuhan) and handsanitizer everywhere

Cost for masks: 0.2$/person per day.

Let's hope that China can ramp up the mask and hand sanitizer production to supply the rest of the world asap, because the west doesn't have the capability.