We use a fractional reserve banking system. Currently the reserve ratio is 10% for large banks. Therefore when you get a loan, 90% of the money you get from the bank the bank conjured from thin air. Loans are backed by 90% nothing.
When I remember applying for student loans from the government, nothing that would be considered collateral by a bank was asked for from the government. Not surprisingly, we see ever increasing NPL rates and larger nominal balances…
Though there was some stuff about having to agree to be enlisted when the draft is made, but you know… metadata drone strikes these days may not always hit the desired target… ;)
With regards to having to pay back a loan, there is always that saying about trying to extract blood from stone…
Student loans are either guaranteed by the government, or there are special rules like you cannot discharge those loans via bankruptcy. Otherwise, banks would not make such loans.
Ultimately, if the loan is not repaid, and there is no collateral nor assets to seize, it comes out of the assets of the bank.
This is still fundamentally different from counterfeiting.
Furthermore, while there are economic models in which loans are collateralized by goods of value exceeding the amount of the loan, modern American loans are generally not that way.
But making loans is a more mainstream way of accomplishing the same thing, and is in fact often considered to promote growth.