The same way we have every time an industry has disappeared in the past: by participating in the newly opened industries.
Is it rough when (for example) shipping crates put a bunch of longshoremen out of a job, when they are in their 50s and too old to easily retrain? Sure. But how many people now not only enjoy (as customers) the benefits that Amazon provides, but also enjoy the employment benefits of a massively expanded global market?
On the other hand, the alternatives are harsher: as the population grows and people resist the very innovation that could create new markets, unemployment will grow. For all the problems we have in the US, providing low unemployment is not one.
You're looking at it with past-tinted glasses. This time is different, and the market won't solve it.
Those newly opened industries have less people in them than the industries they replace. Mostly because our consumption doesn't increase as much as our efficiency does.
Funny you mention Amazon. We enjoy their services, and they enjoy that expanded global market. And they do this by killing local businesses with their ruthless efficiency. (Remember we're supposed to be competitive. There will be winners and there will be losers.) They don't create nearly enough jobs to compensate for the unemployment they cause.
There's also the problem of skill. For instance, in 20 years, truck drivers will be gone. Instead, we'll have an operator managing a fleet of 50 trucks from some control centre. The rest will have to find something else. But what exactly? The low skill jobs will be even scarcer than they are now, and the high skill jobs will be taken up by people who enjoyed a higher education in the first place, as they are now. You could still raise the level of education, but that will be too late for those drivers.
Keep this up to its logical (and absurd) conclusion, and half the population will starve to death in the streets. They're useless, why the market would support them? Of course, we'll have cleaner robots wipe it all away, cleansing the stench of death —those who still have value will be able to enjoy their walk in the park undisturbed.
More realistically though, we'll have a revolution before we get to this point. Or, the rich and powerful will see it coming, and start giving bread and games to the people. Come to think of it, they already do it to some extent.
50 years ago, who would have thought of search engine optimization as a job? Social media manager? Video game storyline writer?
I'm not saying that people who are displaced will easily be able to retrain to a new job. They will have a rough time, and that's something we need to address as a society.
But assuming that number of "jobs" for humans will decrease to zero is a big stretch. I think that even if we had robots that could take care of all our needs for us, humans would come up with jobs to occupy their time.
> But assuming that number of "jobs" for humans will decrease to zero is a big stretch.
It seems to me the amount of available work is steadily decreasing right now. Perhaps not towards zero, but we don't have to lose that much to need substantial reform. Once you reach over 30% unemployment, you have a big problem already.
There's an easy way to increase the number of jobs though: share the existing ones by reducing the work-week. We could start by shaving off a few hours, perhaps as much as a full day (for a 4 day work-week). Then decrease it further to match progress in automation. Of course, we should keep the salaries at the same levels, lest machine owners will just get a bigger and bigger share of the pie, just because they had starting capital the other workers didn't.
All the jobs you've listed are white collar and require a probably at least above average intelligence. The high school dropout you remember from your childhood (the one who sniffed glue and never completely comprehended basic fractions) is not going to be a video game story writer. Once he got his issues in order, he made for a good truck driver though, and was a valuable member of society. I'm afraid it won't be so in the future.
50% of the population have an IQ below 100. 16ish percent have an IQ below 85. What are they going to do?
We've already essentially phased out the useful work that people under IQ 70 can do. It's likely that it's creeped up to 75 or 80, even. As these are automated, let's creep it up to 90.
It also takes out those who are poor and have no branch on which to gain experience for their first job. If we have eliminated the first jobs for all but the most talented and those with connections, what does a somewhat bright poor student do?
Well, it used to be they got a job, proved themselves, and worked their way up. Now, what do they do when they don't have the social capital to get to the point where they can work up?
What are these newly opened industries that will work with these people?
Food delivery service for one. Startups like uber eats and foodora give jobs to people who like to ride fast on bikes, bike deliveries existed before in major cities but not like this.
Is it rough when (for example) shipping crates put a bunch of longshoremen out of a job, when they are in their 50s and too old to easily retrain? Sure. But how many people now not only enjoy (as customers) the benefits that Amazon provides, but also enjoy the employment benefits of a massively expanded global market?
On the other hand, the alternatives are harsher: as the population grows and people resist the very innovation that could create new markets, unemployment will grow. For all the problems we have in the US, providing low unemployment is not one.