Students who head overseas after completing their tertiary education tend to have bigger loans than those who stay and work in New Zealand.
They are also more often than not in their mid-20s to mid-30s and have successfully completed university degrees - often in fields such as engineering, commerce, natural and physical sciences and architecture and building.
New Ministry of Education research into student loan users has revealed nearly 62,000 students have gone overseas since leaving study from 1999 and were still there in 2010.
Those who departed were disproportionately aged between 25 and 34 and had successfully completed studies at higher levels, often at a university.
However, the report also says that although people with degree-level or higher qualifications are more likely to be overseas, they also tend to return home again - usually within three years - indicating most are only gone for the traditional Overseas Experience.
The ones who have student loans and have not returned have generally made less progress on repaying their student loans.
"Those who stay away make little or no progress in repaying their loans. The majority owe more than when they left study."
But, those who did return tended to make substantial progress on repaying the loans, usually because they tended to have "higher qualifications which lead to higher earnings".
Looking at the types of graduates who left New Zealand, the report found that those who had studied in more vocational fields, such as education and health, were less likely to go overseas in the first place.
By comparison, there were high levels of overseas-based graduates who had studied commerce and engineering - "two fields where there are usually thought to be good employment prospects overseas".
"There was a high proportion of graduates in science overseas also, possibly reflecting a perceived shortage of opportunities for science graduates in New Zealand."
Tertiary Education Minister Steven Joyce said that although some highly qualified graduates left New Zealand, others arrived from other countries with similar qualifications.
He said good progress was being made in getting overseas borrowers to start repaying their loans.
Since the start of a campaign in 2010 targeting 1000 Australian-based borrowers, $12 million in overdue repayments has been collected, although a handful of graduates have continued to ignore their obligations.
That prompted Inland Revenue to threaten legal action late last year. Of the 45 people who were sent final-demand letters, 26 have now been in contact.
Legal action has begun against the 19 others - who could end up having assets seized or being declared bankrupt and some of whom will be ordered to repay their entire loan, not just the amount overdue. The campaign has been deemed successful and is being expanded to Britain.
IRD assurance manager Richard Owen said he would continue to build on what has been done to get overseas-based borrowers back on track.
"Our strong message to borrowers is not to wait to be contacted, because the longer you wait the more interest is accumulating and the more you will have to pay.
"You may have gone away, but your loan hasn't. Get in touch with us now and we will be able to work together to get your loan back on track as soon as possible."
There were 97,392 overseas-based borrowers at the start of this year - 47,036 of whom were in default and owing nearly $308 million.
Australia pay lures NZ graduates
When Rafferty Fox graduated from university with a bachelor of civil engineering degree and a $41,000 student loan (right), he did his best to find a well-paying job in New Zealand.
It took "three months of driving around the country" before he found something - a job in Greymouth - but the pay, at the same amount as his loan balance, was far from great.
"I wasn't happy with the work I had. I took a job because I had to but it wasn't what I wanted."
A year later and with only $7000 paid off his loan, he took his skills to Australia. Now in Perth, he earns $71,000 a year, plus bonuses and about $200 a day in allowances when he is on site.
"It's effectively tripled the money ... There's not enough engineers to fill the roles over here so whenever they can find one they grab them.
"You look at my class group and I'd say more than half would be working overseas now. In the past year I have had about eight or nine people from my class move over here."
Since he moved to Australia a couple of years ago, Mr Fox's student loan has crept back up again and is now about $38,000.
He automatically went under the "repayment holiday period" for the first two years but is now paying back the minimum repayments - about $3000 a year. That amount doesn't lower the balance when interest is added but the 25-year-old does plan to pay back his debt in the near future.
He says it's only fair that those who have had help to get through tertiary study repay their loans - an opinion shared by most of his mates.
"Some of us actually feel quite bad about it. We get a loan ... and we wouldn't be here without it so we feel obliged to pay it back."
Mr Fox hopes to do an OE soon - using the final year of his three-year holiday repayment period while he goes backpacking - before returning to Australia and putting a large portion of his income into paying off his loan.
While he would love to return to New Zealand, he says the low rate of pay makes that unlikely. "I love New Zealand and I always come home once a year but I can't see myself working there."