> can the real economy sustain the population...?
> Do we have the resources or not?

It's strange to see that these comments are not exceptions but the norm. How can you be serious? (Or are you?)

We have a productivity orders of magnitude higher than anyone could ever dream of. A tiny fraction of the population is needed to produce the things necessary for living - the vast majority of people are doing "non-essential" work.

We may not be able to give everyone vacations abroad, a 2nd car, a road to their isolated dwelling in the middle of nowhere. We sure are able to give everyone the basics needed for live - and then some. With "we" I mean the industrialized countries. Although, when it comes to feeding the world even that may be doable in entirety, the problem there isn't production but distribution, so a lot of it are local problems we cannot easily influence.

A big reason for the huge military spending is that politicians try their hardest to keep the plants in their districts running - "for the jobs". We have a hard time finding work for a lot of people, and - just looking at http://dilbert.com/ - those who have a job are by no means all doing useful work, not even close. If we drastically reduce advertising, for example - by definition most of it a luxury, stuff that people need doesn't need to be advertised, just make it available - we un-employ a large amount of people not just in marketing but also producing the stuff people don't really need. But yes, let's ask with real concern, "how can our economy possibly take care of all those people?". Yeah, I really don't know, it's such a mystery.

And the argument in other comments "everybody should start saving early, if they don't it's their own fault. Let's roll with that for a moment.

Let's assume all people are reasonable and start saving for retirement early. For this assumption we need to disregard the large number of people who are unable to save anything (all their own fault).

If everybody starts saving early and saves enough for retirement, what is the difference between that and letting the government do it for them (the basic, minimum level)?

The difference is that you can't blame someone "it's your fault" any more, which seems to be a convenient excuse and distraction. It's not like anything in the economy works any better just because you force people to make decisions for which the vast majority is not qualified to do. Which is actually fine! Why on earth does everybody have to be in the business of business-forecasting (where to invest)? And if you say "use index fund", well, if it's so automatic then the government can just do it for you, if there is nothing gained by involving the people because they don't actually get to make investment decisions. Which is fine - humans have invented something called specialization, and to a very high degree. It's absurd that everybody should be "financially literate" to a degree that they manage their own retirement account. (And again: If the argument here is to use something simple as a savings account or index funds I repeat that then there's even less of a point of forcing people to do it.)

Not to mention that on the level of the economy you cannot save for the future. Not unless "saving" means things like not taking minerals out of the ground now so that they can be taken later. Everything else is a circle, and an ever changing one. What people eat and where they live in 50 years cannot be "saved" now - how does that look like, we keep areas for agriculture "frozen" to be unfrozen in 50 years for those living then?

That "you must save" argument conflates business thinking with economic thinking, which take place on completely different levels. From a business perspective you have input and output and from where to where you don't care about, and yes you can "save". But on the level of the economy you see the whole picture, where every input is an output and vice versa, and "saving" simply means shifting the stream of activity and goods in the economy between consumption and investment (which in this context means actually building stuff, not "financial investment", making money wit money).

And, slightly related, it's good when a business saves a few million dollars. When the economy "saves" it means less economic activity. When we don't build that #### that costs 5 billion - and don't do anything else with the same resources - it means there will be 5 billion less in income for businesses and people. So not doing #### is fine when there are better alternatives, it's not so good when there aren't.

In this context I recommend "The Secret History of Silicon Valley" - sounds ominous, but it's just a regular presentation of the Computer History Museum in Mountain View (believe me, it's so worth it!): https://www.youtube.com/watch?v=ZTC_RxWN_xo The TL;DR for the video: SV was made possible by HUGE amounts of very free spending of the US government on R&D during WW II. Private capital only came later, with that base established. And the best thing: They spent money they did not have (US debt made a very big jump during WWII).