**Disclaimer** I am not in any way affiliated with NIIED except to be a KGSP recipient. All opinions are based on my personal experience in Korea.
So, the Regional University quota versus the General University quota still seems to be a mystery to some (or many).
The Korean government’s apparent objective with the regional university quota is to attract talented people in STEM fields (specifically natural science and engineering) to universities outside the Seoul area. Keeping this goal in mind lets look at how that should affect your decision for your KGSP application.
Stage one: University selection
Say you are choosing between two universities that are roughly equal in prestige and are equally difficult to get into. One is a university in Seoul and one is designated as a “regional university.” There are 30 people applying to each of them. Based on their applications each person is ranked from 1 to 30 and the people at each rank are the same as each other (the first ranked people at each school got the same score as each other, the second rank people got the same score, and so on). Also, assume that all 30 are qualified for acceptance into the university, so the only thing that would prevent them from being accepted would be the quota that NIIED sets for university recommendations to KGSP.
You are an engineering major. If you apply to the school in Seoul then you must be one of the top 20 students, no matter what. (This is in a simplified universe where all majors are equally valued by the university. Obviously, in the real world, they may choose someone farther down the list because they want/need people from a particular major, or there is some personal relationship, or any number of random reasons.)
But, if you apply to the regional university then they get three extra spots specifically for natural science/engineering majors. (It used to be three, but it might be more or less now.) If you are in the top three students in one of these fields then you will be accepted, no matter what your overall rank is. For example, even if you are last in the ranking, if all 29 of the other people are majoring in history, psychology, business and philosophy then you can still be accepted. Also, even if you are not one of the top three science/engineering students, then you just need to be in the top 20 out of 27 students instead of 20 out of 30 at the school in Seoul.
Stage two: NIIED selection
The exact same situation applies for the NIIED phase of the selection process. Now instead of being compared to people applying to one university, you are being compared to people from your own country.
Say that 10 people from your same country have been recommended by various universities. Your country has a quota of 2 people from regional universities and 3 general spots.
Again, if you have applied through a regional university in a science or engineering field, if you are one of the top two students who fit the regional quota, then you will be accepted, even if you are objectively ranked below everyone else.
But what if you aren’t one of those top 2 students? The quota for general applicants is bigger that the regional quota, so wouldn’t it be an advantage to apply just for a general spot? This is where you have to remember the original goal of creating regional university quotas in the first place. The whole idea is to attract smart people in STEM fields to non-Seoul universities. If, of the 10 students, the top five ranked people are all regional quota candidates does it make sense to reject 3 strong candidates in favor of people who don’t fit the regional quota? They are trying to bring people to these regional universities, so why would they turn them away?
The answer is that they wouldn’t. If all five of the best people applied through the regional quota then they will likely use the entire quota for that country for these five people. In other words, there is a maximum limit of three people that they will accept from outside the regional quota, but they may accept fewer if the regional candidates are strong. This works out in the following way:
Rank 1-3: Definitely accepted
Rank 4-5: Maybe accepted if one or more of the 1-3 ranked students were in the regional quota
Rank 6-10: No chance to be accepted
Rank 1-3: Definitely accepted
Rank 4-5: Definitely accepted
Rank 6-10: Maybe accepted if only one or fewer of the higher ranked students were in the regional quota
So you can see there is a definite advantage to choosing a regional university if you are in a natural science or engineering field. But, like all decisions in KGSP there is an element of uncertainty. If everyone decides to go this route then there will be more competition, but it is likely that the attraction of Seoul and its universities will balance against the attraction of a slight advantage in the admissions process. This is not a guaranteed process even for very weak students. You will still need to meet the standards of the KGSP program and for the university that you choose. Universities don’t necessarily have to fill every quota if there are not enough qualified students. But, if you think that you are a good candidate for the university, but worry about competing with others from your country who will be applying in Seoul, then the regional quota may be a good choice for you.