What if the university didnt issue paper certificates and only published on their website the names of graduates who kept up their loan repayments. If you failed to make a repayment then your name would disappear from the website and you could no longer officially prove to a potential employer that you had graduated. Wouldn't that reduce the rate of student loan defaults?
That threat seems awfully weak I'd like to think that most employers would be willing to accept even though the website took my name down I still had the education in my brain and would still be the same employee even though my name wasn't up on the site?
Screenshots are easy to fake - that employer would get dozens of applicants claiming they graduated but saying they only had a screenshot to prove it. Only a few would be telling the truth. Under those circumstances the employer would simply reject them all.
If that would happen as you say, wouldn't it create a self-perpetuating cycle where you couldn't make repayments once you lost a job, because you couldn't get another one?