Hong Kong ranks #1 in life expectancy at birth (in 2016) according to the Japanese Ministry of Health, with women at 87.3 years and men at 81.3 years. Our high university rankings seem less important in comparison.

I find it quite surprising that we rank so well. Many factors seem to work against us: dense living spaces, air pollution, and high pace lifestyle. But apparently we also have many advantages: excellent public health care, low violent crime and natural disasters, close family support, and easy access to amenities/outdoor activities. Other advantages are surprising: healthy diet (Cantonese food is known to be greasy but abundance of fresh seafood and vegetables helps), and being a big city (stressful lifestyle is counterbalanced by easy access to hospitals).

Hong Kong’s life expectancy has increased significantly over the last 50 years (from 67.8/75.3 for male/female in 1971 to 81.7/87.7 in 2017). That’s an incredible increase, in my own lifetime! A 50% decrease over the past 30 years in smoking in Hong Kong is credited as a key factor. Before the 19th century, life expectancy globally was 30-40 years at best. Good news: there is no scientific evidence that there is an upper limit to life expectancy. Bad news: life expectancy for people born on my birth year is way below my current age, so every day I am alive is a “bonus”!

Longevity does not necessarily equal quality, something that perhaps Hong Kong still needs improvement. We also have to deal with chronic diseases that were less prevalent when life was shorter: cancer, diabetes, etc.

While each of the factors seems to make sense, each by itself cannot explain the rankings. For example, the US is reputed to have excellent health care, but it is not even in the top 10. France is known for its tasty but rich diet, but its females ranked number 4 (85.4).

I wanted to have a more scientific understanding of all these. It’d seem that given the rankings, and the availability of accurate data for many of the factors (healthcare quality, pollution, etc), it should be possible to do a standard statistical analysis and identify which factors contribute the most to the rankings. However, even after many searches online, I have not been able to find such an analysis. A well-trained statistician should be able to perform this task easily.

Since I don’t have the time or expertise to do this myself, I studied the rankings more thoroughly. It turns out that, in addition to the rankings provided by the Japanese Ministry, the US CIA also keeps a publicly available list of life expectancy (who would have thought!) Here are some rankings on the CIA 2017 list: #1 Monaco (89.4 years), #2 Japan, #3 Singapore, #4 Macau, #7 Hong Kong (83.0), #10 Switzerland, #21 Canada, #40 Taiwan, #35 UK (80.8), #43 US (79.6), #102 China (75.7), #105 Saudi Arabia, #224 (lowest) Chad (50.6). The top ranked countries/cities are mostly Asian/European, and the bottom ones are almost exclusively African. The difference between #1 and the last is a whopping 49 years. This is an extreme form of inequity in the world – not wealth or material comfort but how long you live!

My own non-scientific conclusion from reading the lists are that the top factors contributing to long life expectancy are: wealth (nobody ranked top is poor but wealth alone does not mean long life, viz US), health care (quite obvious), diet/nutrition and personal safety from social violence and natural disaster (Japan fell behind Hong Kong right after the Fukushima disaster, and your chance of dying is much higher if your country is at war). Family support should be very important too. My hunch is that Hong Kong’s high ranking must be at least partially due to our wide use of domestic maids – not only do they take care of our elderly, they also help relieve the stress of the younger generation in taking care of them. And of course, on their Sundays off, we enjoy semi-forced multi-generational family gatherings at yum cha! Let’s be thankful to our maids!

And let us salute our females for earning the honor of the longest living homo sapient, even though I am jealous of their 6+ years of life than us males!