If we ever have a contest for the “Golden Age of Man”, my vote is for the last 200 years. Ancient Greece would probably get more votes for inventing philosophy, Democracy, dramas and comedies, and classical architecture. Which is a pretty good argument. But I have a stronger argument. We have more people! I don’t mean that people today are any better (or worse) than those from any other time. I mean that there are numerically more people today than ever before!

Greece might have great art, the Romans might have a mighty empire, but the 21st century has more living people than any other period of history. Every generation since before the pyramids has valued people as the primary source of wealth. Only people could labor! Only people performed work! True… tools, or a horse, or maybe a tractor can make a farmer more productive, but it is only the farmer that can harvest the crops.

The same is true with blacksmiths, bankers, ship makers, artists and any other human occupation. Global population has slowly risen throughout history, with occasional big drops due to plague, war or natural disaster. A growing population produces more and consumes more. Rising population has always gone hand in hand with rising wealth.  Before the year 1 A.D, global population rarely got above 250 million yet now it is 7.6 billion. And never before have we been so wealthy, with such a small percentage truly poor.  

We also live longer than ever before. Long-life may not in itself make you wealthy, but if you are wealthy a long and healthy life certainly has more value than a short one. 2000 years ago Romans lived 30 to 40 years. Today we live until we are 80 years old. Mostly because children that are born today live until they become adults. That’s something new. In other societies, few children grew to maturity. Childhood diseases and the dangers of life meant that only one child out of 5 or 6 became an adulthood.

Between the need for food and resources and high rates of childhood death, humanity was on a treadmill. We needed a lot of children and new adult workers. The population grew dramatically in the last two hundred years, but productivity grew even faster. More people produced more wealth faster than ever before.

This steady march towards higher population and greater wealth will all come to an end as we reach 11 billion in the year 2100. After that, population retreats, and billions will disappear from around the world. Never again will there be so many people on earth. But if we can keep our wealth even with fewer people, it might be a very good thing.

Technology has been an important wealth multiplier. Today’s worker is far more productive than their predecessors. Transporation is faster and cheaper.  It takes less effort to produce a given good. New farming techniques and seeds produce far more food. America’s greatest efficiency expert, Peter Drucker, said that farms and factories became 50 times more productive in the 20th century. Every human being on earth benefits from this greater productivity.

Consider how this increase in efficiency has impacted our workforce. In 1850, 70% of all American workers were farmers. Today farmers are 1-2 percent of the labor force, and these remaining farming jobs will be automated away in a few years. Next, factories became the main source of American employment, peaking in the mid-1960’s. Today, factories are a mere 8% of the workforce and falling. Robots and artificial intelligence will replace the remaining industrial jobs in 10-15 years.

Today, we have a service economy, combining low paying workers (cashiers, fast food workers, taxi drivers, warehouse workers) and highly paid knowledge workers (lawyers, stockbrokers, researchers, software developers). All of these positions have been targeted for replacement by automation, robots and artificial intelligence.

Tools and machines have always improved human productivity, but only lately have they replaced human beings directly, and in large numbers. Early farmers managed their own fields, but with a tractor, more fields could be plowed. Today’s farming equipment has created farms without farmers. Factories have introduced robots that replaced large numbers of workers, but outside of the structured environment of the factory, older robots have had limited impact.

Newer, intelligent, robots are able to able to deal with the ambiguities of the “real world”. Self-driving cars work in all weather, and traffic conditions. “Lights out” factories are able to work without human supervision. In corporations, sophisticated work functions such as performing sophisticated procedures, researching lawsuits, or selecting stocks for an investment fund have all been performed by machines with increasingly little or no human intervention.   

This breaks the labor treadmill. If machines are workers, more robot-workers can be built without growing our human population. Of course, such a major change will create major “disruptions” throughout the economy. By the second half of the 21st century, the old and new economies will clash. 

Look at China, the world’s most populated nation. China will continue to grow for just five or ten years, reaching a peak population of 1.5 billion. Then population will tumble by 500 million citizens by the end of the 21st century. Before population growth stalls, Chima will have an aggressive automation program in place. China is already the largest buyer of industrial robots but has started to buy robotics companies. By the 2020’s, they will build the majority of the world’s robots.

In order to meet their own needs, China must create the ability to produce millions of robots every year. After their own needs are met, by the mid-2020’s China will produce many times more industrial robots than the entire world produces now. Each of these millions of robots will replace 10 or more workers, driving a wave of automation across the world. Today we worry about jobs moving offshore. In the future, it won’t matter where the work is performed, if robots replace people.

Some believe that transitioning to robotic labor will take much longer, that people won’t accept such massive changes in a short period of time. But some nations have already achieved high levels of robot integration. For every 10,000 workers, China has only 75 robots; in the US that rises to 175.  But the nation with the highest robot ratio is South Korea, with 531 robots.

These ratios are not guesses at the future, rather they are milestones in industrial production. Just as farmers in all developed nations have dwindled to just 1-2 percent of the labor force, we can expect manufacturing workers around the world to achieve these ratios. And then exceed them.

For China to match South Korea’s average robot ratio, 4.5 million robots must be installed. But that’s just an average. In the automotive industry, which is more heavily automated than the average workplace, the US has  1,300 robots per 10, 000 workers. Attaining the automotive ratio in just the US and Europe will replace tens of millions of workers. While just industrial models have been discussed, the same level of automation will be achieved in banking, legal, insurance, and other “knowledge” based professions.

With robots and automation, the treadmill of ever-larger populations to achieve ever greater wealth is forever broken. We can add machines instead of adding people to mine resources, grow crops and build housing. In the past, the expansion of human population has forced humanity to transform the earth. When our population was in the low billions we began to run out of food. So we found out which seeds grew best on what land. Then we invented artificial fertilizers and pesticides. Now we are altering the genes of plants and animals to increase productivity. Without this boost from science, the world would have starved to death years ago.

Not enough food, fighting over water, worn out farmland, air and water pollution, whole species fished out of existence, all the result of population pressures.  Yet by the end of the 21st century, we will reach peak global population at 11 billion. We will no longer need to grow. In about 25 nations we already see a stable or falling population.

If it wasn’t for immigration, population growth in the US would have stalled. Our fertility rate, the number of children women give birth to, is 2.0. That’s our replacement rate.  But Russia is just 1.75,  Germany 1.5, and Spain just 1.2. Take Bangladesh. In 1982 their fertility rate was 6.1, but in 2015 it was just 2.1… and falling. All of these numbers are just milestones along the normal curve for developed nations.

The United Nations projects that by 2200 the world’s population will be between 2 and 5 billion. And population will continue to shrink. That gives fish room to repopulate the ocean, exhausted farmland has time to regenerate, and for the carbon in the can be absorbed by trees and plants.

In the 23rd century, human population may continue to drop. But along the way, we will hopefully have found a source of free power to join with unlimited labor. Whether that power is renewable, nuclear, fission, or something else… joining free power with robotics will create goods that are so cheap that they are essentially free. The rich may be even richer than today, even the poorest of people will be able to have more than enough to meet their needs. So, here’s to the 23rd century, to sub-1 billion and to the next Golden Age of Man!