Let's look now at the age profile of the world population. What you can see here are a number of curves, which are referred to as population pyramids. I've got six of them here for six different countries and you can see that they have quite different shapes. On the left hand side of each pyramid, we have a distribution of the age of males. On the right hand side, we have the age distribution of females.
Let's look at the population pyramid for Australia. What we can see is that perhaps past the age of sixty, the population of both males and females starts to taper off and that's essentially, the effect of people dying of old age. You can see that around the age of thirty to thirty five, there is a bit of a bump in the population and that would reflect either a spike in the birth rate thirty to thirty five years ago or perhaps, a surge in immigration into the country.
If we look at the population pyramid for Japan, we see that it has a very, very different shape indeed. We can see a taper down here and what that indicates is that the birth rate in the country is falling off. We can also see that the Japanese are very long lived. There are many more people aged above eighty than there are in Australia. We can also see that there is this large area of people aged above effectively forty-five. This means that they have quite a large proportion of elderly people in their society with not too many young people coming in to replace them.
The curve for Germany, you can see it's also quite different. It's got this big bulge in the range fifty to sixty which indicates something about a population boom that started nearly sixty years ago.
The population pyramid for China has got a number of quite interesting lumps and bumps, which probably reflect many events in the history of that country.
The population pyramid for India also has a very unique shape and effectively, represents the fact that the life expectancy in India is much less than it is in countries such as Australia, Germany, United States or Japan.
Now, what I'm going to do is to highlight a band of ages, the ages between twenty and sixty. These are working aged people in these societies. So, people less than twenty are generally being supported by their parents. They're typically at school or at university. Those above sixty have retired and are being supported either by the state or by their children.
So, a really important concept in understanding populations is what’s called the dependency ratio; that's the ratio of the number of dependents, that's children and older people to the number of workers, the people who are earning a salary, doing a job and supporting the young and the old people.
For dependency ratio, a low value is good. The dependency ratios that are plotted here are for Australia and we can see that they achieved a minimum in the year 2010, that's when the dependency ratio was the best it could possibly be. As we move forward in time, the dependency ratio grows. In fact, it gets worse, that means that there are more elderly people and young people to be supported by a smaller number of working aged people. So, the only way we can keep our society working the same way as it has is we need each individual person to become more productive or we could add robotic workers to the society, to increase the amount of work that's going to be done without requiring more human beings.
The bottom line is that in the future, if we want to have the same standard of care for young people and elderly people and it's going to be provided by a smaller number of working aged people, then those working aged people need to be more productive. Each one of those people needs to do more work than people have to do today.
So, that's what we have to look forward to. Each working aged person having to do more work than people did a few years ago. The alternative for that is we introduce into the mix, robotic technology that means we introduce robotic workers. So, they either do some of the work themselves or they help the human workers to become more productive.
Let's look here at health care versus age and what we can see quite clearly is that for very young people, they require certain amount of health intervention and then for the early years of their life, perhaps from five through forty, they don't require too much health intervention but above the age of forty, people need on an individual basis, more health interventions. It basically means elderly people require more health care.
So, as our population gets older, graphs like this are going to get much, much more extreme and that presents a real challenge to us as a society to provide the health care that needs to be provided. If you've ever visited a hospital, you know that they are incredibly busy places. There’s all sorts of work going on. There is work moving people from one ward to another. There are surgeons performing operations. There are people doing laundry. There are people doing cooking. All sorts of activities happening in a hospital employ a lot of people and that make it expensive.
So perhaps, robot technology has a role to play here. Robotics is already making quite a significant impact in the area of surgery. In fact, it's more technically teleoperation. What we can see here are some surgeons, teleoperating or controlling small robotic implements inside the body of a patient over here. So, these are the robot arms that are doing the work inside the human body. These people here are controlling those robotic arms.
The advantage of doing this sort of surgery is that the surgeons can be more productive and because we make very small incisions in the patients, they recover much more quickly having to spend less time in hospital and that's a net benefit to the health care system.
Other sorts of robotic technology that are being proposed for hospitals include instruments that move themselves automatically from one ward to another and robots that can pick people up, perhaps lift them from a wheelchair into a bed or from a bed into a wheelchair. A lot of operations in hospital involve moving people from one place to another. People are heavy and will require quite strong people just to move patients around.
Humanoid robots such as Asimo shown here, might be able to provide assistance to elderly people in their own homes. If we can keep people healthy and happy in their homes for a longer period of time, then we reduce the amount of time that they need to spend in elderly care and that is a net advantage to society. So perhaps, robotic helpers in the home can assist people staying in their homes for longer.
Our population is getting older. Let’s look at how this ageing varies across countries, the problems it will create and how robots might help.