The US has a very complicated system of multiple, income-based, student loan repayment schemes[1]. 20 to 25 years of repayment based on many factors. It is so complicated the government has created a "Repayment Estimator"[2] to help people choose the best plan. At a glance it looks similar to the New Zealand 8%. Seems like most systems evolve to where they are impossible for a human understand. See tax code, social security, Obamacare, etc.

[1] https://studentaid.ed.gov/sa/repay-loans/understand/plans [2] https://studentloans.gov/myDirectLoan/mobile/repayment/repay...