There are more than 100 'international days' recognised by the United Nations. Some of them you might have heard of (International Women's Day, for instance). Others you might not have heard of (International Mother Language Day).
Some of the days are light-hearted and fun (World Tuna Day), and other days less so (World Intellectual Property Day).
There is one international day, however, that is slightly more difficult to pin down. On the one hand, this day celebrates human flourishing and the collective potential of our species.
On the other hand, this day serves as a warning, alerting us to the dangers associated with humanity's rapid, unchecked expansion.
11 July was World Population Day.
It was established by the UN in 1989, following the wave of interest generated by the Day of Five Billion, which was observed on 11 July 1987.
Since then, the global population has swelled at an even faster rate, adding another 2.8 billion to its ranks.
Having to accommodate roughly 7.8 billion people is no easy feat: it puts immense strain on everything from agriculture and the environment to water and sanitation systems, the provision of public welfare, and access to living space.
As the result of population growth, people are not only more numerous, they are also older. Ageing has also taken on a new meaning, seen less as a public burden that needs to be managed and more as a new stage of one's life with fulfilling potential.
As such, ageing populations are proving to be one of most significant demographic transformations of this century.
Fortunately, both the public and private sector is responding to these demographic shifts. This is good, not only for the millions of elderly people that depend on supportive care, products and services, but for the sectors with revenue exposure to senior consumption.
We call this the 'silver economy', within which lies significant growth potential over the coming years.
The silver economy refers to economic activity generated by the spending linked to serving the needs of those over 50. And this is big business. The US silver economy is worth $7trn alone, making it more valuable than the economies of Britain, Japan, or India.
In the past 18 years, companies whose businesses relate to the ageing population have achieved average revenue and earnings growth that has outperformed the global market. This trend is expected to continue gathering momentum.
More and more sectors will be driven by the spending of seniors, as these high-net-worth consumers are those with the fastest growing expenditure rate among the overall population.
With more spare time and disposable income, industries such as health, social care, leisure, and travel are benefitting significantly from growth in this consumer segment.
A broad church
The silver economy is broader than you might think. Automobile companies, for example, stand to benefit, as former baby-boomers change cars more regularly than today's millennials. Beauty and personal care companies may also profit, as pensioners seek to look younger for longer.
And for those over 80, home security companies are particularly important, experiencing strong growth as a result.
The silver economy does not show up in the same way everywhere. Each geography has its own sector profile, diversifying the universe of investment opportunities.
Asia, for example, is focused primarily on leisure activities while Europe is focused more on financial savings and dependency.
While countries like Japan and those in Western Europe have been growing old for decades, investment opportunities are beginning to open up in emerging countries.
This applies particularly to public health, where economic development and cultural westernisation is causing an increase in lifestyle diseases traditionally experienced by wealthier countries, such as diabetes.
There is one public health factor, however, shaping trends in ageing more profoundly than anything else: Covid-19. It is. of course, impossible to broach the subject of ageing without exploring this; the single, biggest threat to elderly people in modern times.
To put this threat in perspective, the chance of dying from Covid-19 goes from less than 1% for the under 50s to as high as 20% for the over 80s.
Naturally, over the past few months, the outbreak has pulled the silver economy in different directions, benefiting some players while disrupting others.
On one side, certain companies, from pharma to food delivery platforms, which have experienced heightened demand, particularly from older consumer segments, have benefited from the crisis.
On the other side, the challenges faced by sectors that have either lost business (such as travel and leisure) or experienced increased costs (health and life insurance) have been compounded by their especially high exposure to elderly consumers.
But while the short-term prospects for the silver economy are mixed, the outbreak is causing us to revaluate the strength of our health and social systems, and the resiliency of businesses associated with elderly consumption. Such a re-evaluation is necessary given the far-reaching economic and human implications of a future pandemic.
This - the long-term impact of coronavirus - coupled with ageing as an underlying megatrend, means the silver economy will continue to grow over the next 50 years. And for savvy investors that recognise and capitalise on this ongoing theme, lucrative opportunities await.
So, as we marked World Population Day, let us take it both as a celebration and a reminder. It is a celebration of human achievement, which has resulted in a higher quality and longevity of life for people globally.
But it must also remind us of the importance of responding to the challenges associated with ageing populations.
Only by investing in the people, companies and institutions designed to support the elderly, can we ensure a long, healthy and happy future for us all.
Vafa Ahmadi is head of global thematic equities at CPR AM