Relatively ancient and inactive
According to my sources, the median earnings of young adults with merely a high school education is $29k. The median earning of young adults with a bachelor's degree is $45k. This, of course, puts them in a separate tax bracket than their uneducated peers. They are paying more in taxes:
Your model is very simplistic. Saying "College students earn more than non-college students, so we should make everyone to go to college" is unhelpful. Those that want to go to college, even expensive ones, can take out student loans, get scholarships, etc. Those that don't want to are pressured by the low price in a more subsidized model, and the effect of education on unmotivated students is questionable. As it is, students have the opportunity, in the current model, to go to college. Further subsidies would just make it easier on them (which is nice, but again, as it is, almost everyone has the opportunity to go), while at the same time slowing down the economy by increasing the taxation rate.
At the very least, the loans should not accrue interest.
I'm not sure you understand why
banks give loans.
But seriously, the debate is more complex than this. There are competing ideologies at play. Are we entitled to a college education? Is it a right? If it's impossible to really get anywhere in this country without a degree, doesn't that mean we should have the opportunity to get one? Or, on the other hand: College is for people who are going to excel and can actually use their degree. There is no entitlement for the average person to have a college degree, it is not a right, but a paid privilege. These ideas conflict, and I believe neither one is perfectly accurate.
I subscribe largely to the latter. I believe that the government has an obligation to ensure that as much of the population has access to higher education as possible, but that that should be the end of government intervention, so as much of the system as possible can be run according to efficient free market principles. The government has done its role in this, as almost all students, even those not particularly gifted, have access to public higher education across the country, be it through loans or otherwise. This has ensured that the education system is not a large obstacle to social mobility. From there on, intervention should be limited, as the free market leads to efficiency, and trying to even out the board further yields diminishing returns on the benefits, while being wasteful with government money.
If you actually want to try argue that people are "entitled" to a college education, go ahead. I don't think it's a very defensible point. If you're "entitled" to higher education, why not "entitled" to free housing (because it's impossible to really get anywhere in this country without somewhere to spend the night) or "entitled" to a free car (because it's impossible to really get anywhere in this country without a car)?
(1) Not all people who would do well in college can afford to go to college.
(2) Not all people who can afford college will do well in college.
If we gave each person 20k a year to go to college, how many of them would squander it? How many good students must it benefit before it considered of value?
The reason I don't oppose the aforementioned is that the money isn't just evaporating. It's going to someone, and that someone is the universities, and I feel like there should be a system in place where squandering it doesn't mean you can get out easily. It shouldn't have to be repaid (or only partially repaid) if you graduate, for instance (since it would then be money well spent). But if you do not graduate, then it should have to be repaid in full.
All of that interest from private loans is going where? To banks? Yeah because they need so much more money. Why not eliminate the interest -- graduates are probably going to spend the extra on stuff they want, which does help the economy and not just one corner of it.
With just requiring 50% of the loans required to pay back, that 80k used to college would turn into 40k, and according to the figure above, the difference would be made up in a little under six years in taxes ($6900 × 6 = $41 400).
I don't think this is a useful post. You're just saying "Oh, yeah, but if we reduced what students had to pay, they'd have to pay less." This issue, like the vast majority of issues, is multidimensional, and focusing exclusively on benefits the students get (with a bad simplistic mathematical model for increased government revenue) is like saying that we should release everyone in Guantanamo Bay because it costs money and it'll make its former inmates happier.