Assuming that someone who died from coronavirus is far more likely to have been tested for the virus than someone who's been infected by it, the true death rate of someone infected by the virus is probably far lower than the calculated death rate. (# of confirmed death / # of confirmed infections).

S.Korea did extensive testing, which reduces the number of unreported infections. So the calculated death rate in S. Korea is 4x lower than a comparable country like Spain, which has similar # of confirmed cases, population, GDP, and GDP per capita.

If we assume S. Korea's calculated death rate(<1%) is closer to the true death rate and apply it to other countries to derive the total # of infections (reported + unreported) based on the reported death count, we can see there may be far more infections than we know.