[burger]

WHO's sitrep 30 (19 Feb) states

The confirmed case fatality ratio, or CFR,is the total number of deaths divided by the total number of confirmed cases at one point in time. Within China, the confirmed CFR, as reported by the Chinese Center for Disease Control and Prevention,9is 2.3%. This is based on 1023 deaths amongst 44 415 laboratory-confirmed cases as of 11 February. This CFR does not include the number of more mild infections that may be missed from current surveillance,which has largely focused on patients with pneumonia requiring hospitalization; nor does it account for the fact that recently confirmed cases may yet develop severe disease, and some may die. As the outbrak continues, the confirmed CFR may change

WHO's sitrep 38 (27 Feb) ginumbers that indicate current values of 4.0% CFR for Hubei and 3.5% CFR for China.

Hubei province: 2641 deaths in 65596 confirmed cases
China (total): 2747 deaths in 78630 confirmed cases.

The larger CFR now compared to 8 days earlier could be due just the maturity of the disease in the area.  Hubei has had more sick people longer, and more have eventually died. Other areas have not had many people sick for as long, potentially meaning that in a few weeks their CFR numbers will look similar. 

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

A few things here.  First, this is not the standard (and best, I think) way to calculate the CFR.  CFR should be an estimate of how likely you are to die if you get the disease.  So, you calculate that as (#dead)/(#dead + #recovered).  When you do that, you get higher numbers than the current estimates in China, but many cases have yet to be resolved, and that measure of CFR is declining over time.

But...as above, this doesn't count the mild/asymptomatic cases that aren't showing up in hospitals or getting tested in China.  How many of those are there?  The Diamond Princess might give us an answer.  They have 4 deaths in 700 cases so far (I think 30+ still are in the hospital with uncertain outcome).  The rest of Japan has 200 cases 4 deaths.  So that implies that the testing regime in Japan at least is only getting ~40% of cases. And that means that CFR may be much lower than currently estimated.

Like I said above, there's tons of uncertainty still.

[burger]

WHO's sitrep 30 (19 Feb) states

The confirmed case fatality ratio, or CFR,is the total number of deaths divided by the total number of confirmed cases at one point in time. Within China, the confirmed CFR, as reported by the Chinese Center for Disease Control and Prevention,9is 2.3%. This is based on 1023 deaths amongst 44 415 laboratory-confirmed cases as of 11 February. This CFR does not include the number of more mild infections that may be missed from current surveillance,which has largely focused on patients with pneumonia requiring hospitalization; nor does it account for the fact that recently confirmed cases may yet develop severe disease, and some may die. As the outbrak continues, the confirmed CFR may change

WHO's sitrep 38 (27 Feb) ginumbers that indicate current values of 4.0% CFR for Hubei and 3.5% CFR for China.

Hubei province: 2641 deaths in 65596 confirmed cases
China (total): 2747 deaths in 78630 confirmed cases.

The larger CFR now compared to 8 days earlier could be due just the maturity of the disease in the area.  Hubei has had more sick people longer, and more have eventually died. Other areas have not had many people sick for as long, potentially meaning that in a few weeks their CFR numbers will look similar. 

If, for whatever purpose, you want to make some other estimate different than CFR, you're free to do so.  But, the 4.0%, 3.5%, and 2.3% are measures, not estimates.

A few things here.  First, this is not the standard (and best, I think) way to calculate the CFR.  CFR should be an estimate of how likely you are to die if you get the disease.  So, you calculate that as (#dead)/(#dead + #recovered).  When you do that, you get higher numbers than the current estimates in China, but many cases have yet to be resolved, and that measure of CFR is declining over time.

But...as above, this doesn't count the mild/asymptomatic cases that aren't showing up in hospitals or getting tested in China.  How many of those are there?  The Diamond Princess might give us an answer.  They have 4 deaths in 700 cases so far (I think 30+ still are in the hospital with uncertain outcome).  The rest of Japan has 200 cases 4 deaths.  So that implies that the testing regime in Japan at least is only getting ~40% of cases. And that means that CFR may be much lower than currently estimated.

Like I said above, there's tons of uncertainty still.