(Yicai Global) March 24 -- Here in Shanghai, life is returning to normal. But it is still not business as usual. My eight-year-old attends Grade 2 virtually, by watching specially-made TV programs in our bedroom. My wife juggles working from home and caring for our three-year-old. I am at home too, trying to ignore the distractions as I put these numbers together.

Friends and family abroad know that the worst as passed in China and they ask me what they can expect. The data show that new cases of the virus have slowed to a trickle and it is not too early to take stock of China's experience. I offer five takeaways.

The first is that strong efforts to restrict movement have big payoffs. The graph below shows cumulative confirmed cases per million people as at March 22. Wuhan would be "off the charts" if I wasn't using a log scale. As a percentage of its population, about 10 times as many people caught the virus in Wuhan, compared to what we currently see in Europe. Infection rates in the rest of Hubei Province are comparable to those of other countries, while those in the Mainland outside of Hubei, are an order of magnitude lower. 

The second takeaway is that, notwithstanding very large differences in the infection rates in the three Chinese regions, the dynamics of the disease have been fairly similar (I begin my analysis from December 31). Based on China's experience, my friends and family abroad should expect the virus to persist for close to three months, with infection rates peaking after a month and a half.

The graph below shows that in the Mainland outside of Hubei Province, the number of new cases peaked on February 3. In Hubei outside of Wuhan, the peak was reached two days later. A second peak occurred on February 12, but this is likely just a data issue. The same data issue obscures the Wuhan numbers, which I indicate with dotted lines. Abstracting from this, the data in Wuhan show a plateau, rather than a peak, which lasted until February 18. Thus, across the three regions, things got worse, in terms of new cases increasing, for between five and seven weeks.

As the flow of new cases slowed, the sick recovered and the number of existing cases began to fall. The graph below shows that it took 6-7 weeks for existing cases to peak in each of the three regions. Subsequently, it took 2-3 weeks for the number of existing cases to fall by half and another week for cases to fall by half again. As at March 22, there were 4700 cases in Wuhan (about 12 percent of the peak) and just several hundred elsewhere in Mainland China.

The third takeaway is that COVID-19 is more lethal than the seasonal flu, but less deadly than SARS. Death rates vary from 5 percent of those infected in Wuhan to 3.6 percent elsewhere in Hubeito 0.9 percent in the rest of the Mainland. It is likely that the Wuhan rates will edge higher. By comparison, the Mainland death rate from SARS was 6.6 percent and the seasonal flu typically kills only 0.1 percent of those infected (in North America). The relatively high death rate in Wuhan shows the challenges that a health care system can face when the infection rate is high. Similarly, SARS had a death rate of 17 percent in Hong Kong. These data illustrate our fourth takeaway – the dangers of not "flattening the curve" and keeping the infection rate below what the health care system can handle. 

Our fifth takeaway is Asia- rather than China-specific. It emerges from the graph below, which shows cumulative confirmed cases per million people. The timing begins when the infection rate reached one-per-million in each country. I show the dynamics over the subsequent 30 days. The data are as at March 22.

It is striking how much flatter the curves are for the three Asian countries – China, Japan and Korea – than for Europe and the US. This suggests a dramatically slower rate of virus transmission in Asia. There are likely a myriad of factors at play across these many countries. But, in Shanghai, there is one fact that keeps staring me in the face: Asians wear masks. My friends and family abroad say that, even now, few people wear masks. In Shanghai, with the outbreak well past its peak, everyone still does.

In the West, the word is that masks do little to protect you if you are healthy and they should only be worn by those who are sick. The problem is that COVID-19 may not show symptoms for up to two weeks, so infected people may be inadvertently spreading the virus. In Asia, we are playing a cooperative game. No one knows who is sick, so we all wear masks. We wear them for the protection of others and, by extension, for ourselves as well.

I have heard stories of people being stigmatized for wearing masks in Western countries. People assume that if you wear a mask, you must be sick, and you should be at home. I think that the Western public health authorities have a role to play in changing that mindset. They should encourage everyone to wear masks. The graph above suggests to me that universal mask usage will lead to a slower spread of the disease. I may be wrong, but the cost of wearing a mask is so low, it seems like a reasonable risk to take.

In many countries, surgical masks are in short supply and need to be reserved for health care workers. This is understandable. In the short run, it appears to me that even wearing a bandana over one's mouth and nose – like an outlaw in an Old West movie – would be preferable to going out bare-faced when the infection rate is rising. Longer term, should the authorities be successful in changing peoples' mindset, masks will become as useful and fashionable in the West as they are here. 

Editor: Xia Ruirui