They are not only an important source of local and national funds, but they also enrich the schools and tertiary institutions where they study. And they play a role boosting the reputation of, and links with, New Zealand if experiences are positive.
Over the years, however, numbers have been topsy-turvy. Good growth was followed by lean years. Numbers decreased after the Chinese student boom of the early 2000s and New Zealand's reputation suffered because of the poor quality of some private training institutes. There was also a national dip through the global financial crisis about 2009 and the Christchurch earthquakes and the loss of student lives in the CTV building collapse did not help. After a relatively quiet period, Dunedin and Otago appear to be on an upswing again.
The message here is that the arrival of overseas pupils and students cannot be taken for granted, whatever New Zealand's natural advantages by being a primarily English-speaking country and relatively safe and peaceful.
First, of course, the product has to be right. That means good experiences and good education. It means welcoming communities and effective study and pastoral support.
But without active and intelligent marketing and promotion, as well as personal and vigorous recruitment, numbers easily stagnate or fall. This applies across the sector.
This, clearly, does not mean developing low-quality courses with the purpose of providing qualifications simply as a means for students to immigrate. The potential to be able to work and live in New Zealand has always been part of the motive for some. This has become obvious in Auckland, and among Indian students, over the past few months.
Auckland and Christchurch, and to a lesser extent Wellington or Queenstown, have one significant advantage over most of the South. Students and their parents - should they choose to visit - have the additional costs, hassles and psycological barrier of being another step removed from the international gateways, erecting one more hurdle. The South must also seem incredibly quiet to students from big cities and heavily populated places.
The latest figures from Education New Zealand claim international students contributed $117million to the Dunedin economy and $142million to the Otago economy in 2015. The news since then has been positive. University of Otago international numbers are increasing, after several years in the doldrums, while the Otago Polytechnic's growth is impressive across its three campuses.
Its Auckland International Campus has grown from 387 Efts in 2015 to 540 last year, its Dunedin campus from 221 to 267 and the Central campus (Cromwell) from 44 to 60. Actual numbers coming are much higher, many for short courses.
Students come from a wide range of countries and backgrounds. For many, the study involves much sacrifice and commitment and they often do not come from wealthy families. Many need to work on foundation studies and are learning English. Others undertake, or move on to, specialist courses.
A significiant drawback for students is when too many come from one place and they, naturally, mix and socialise mostly with their own. That might be easier on them, but it fails to advance their English as much as it should or expose them so much to what the South has to offer.
One of the lessons for providers is that they should not rely too much on one source. For reasons outside their control, the tap can be turned off. From that point of view, the university should be pleased. Of 2592 international students in 2015, 20 or more were from 23 different countries. The United States (656), China (458) and Malaysia (254) led the pack.
