The CDC is now estimating the R0 at 5.7, which is really high, and seems much more likely given the extremely rapid spread in areas like NYC.

https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article

Abstract

Severe acute respiratory syndrome coronavirus 2 is the causative agent of the 2019 novel coronavirus disease pandemic. Initial estimates of the early dynamics of the outbreak in Wuhan, China, suggested a doubling time of the number of infected persons of 6–7 days and a basic reproductive number (R0) of 2.2–2.7. We collected extensive individual case reports across China and estimated key epidemiologic parameters, including the incubation period. We then designed 2 mathematical modeling approaches to infer the outbreak dynamics in Wuhan by using high-resolution domestic travel and infection data. Results show that the doubling time early in the epidemic in Wuhan was 2.3–3.3 days. Assuming a serial interval of 6–9 days, we calculated a median R0 value of 5.7 (95% CI 3.8–8.9)

So, what is your verdict? This only confirms the OP’s claim that the R0 might be much higher than expected.

Just wanted to give the information. The facts speak for themselves.

Ok, considering that the OP was heavily downvoted without anyone voicing concerns, I am frankly not so sure about that.

That is high, but that study assumes a serial interval of 6-9 days, which is on the far long end of estimates I’ve seen (~4 days).

That basically explains the difference...