On Feb. 10, I was informed by telephone of the interview. It was to be conducted on Feb. 17, 10:50am at CUHK's Econ Department. I was also told that the interview would last for about ten minutes, and that I should bring with me my HKID. Formal dressing code was advised by the lady.
Before the day of the interview I search online forums about this interview, and found little resources. Some report that CUHK's panel will ask technical questions depending on your area and courses you've taken, ranging from the IS-LM model to the assumptions in classical linear regression. Since I was participating in the MCM contest day and night for four days only one day before the interview, and I had homework to finish and lessons to go to in the only day in between, I really had little time to prepare. However, I still managed to dig out my Intermediate Macro and Econometrics textbooks to take a look at relevant graphs and theorems. That was the little preparation I did.
I left the student residence of HKBU at about 9:25 on Feb. 17. It was only four train stations to CUHK, so I was not in much hurry. In fact it only took me a little more than half an hour to get there (including the walking), but I think that is not unnecessarily too early because I think I benefited from the extra time in reviewing what I had prepared and gaining some confidence. I called the secretary and told her that I'd arrived, and she told me to report myself after 10:30 at the office facing the interview meeting room. During this period I made out the IS-LM model in my mind and committed the classical linear regression assumptions to memory.
There were three other students waiting outside the meeting room by the time I went there. I signed on the name list, and began conversing with the students. The one to be interviewed immediately before me was a CUHK mainland student majoring in Math; the other two, interviewed after me, were from the MS program at HKUST, and who had done their undergrads at Nanjing University and Zhejiang University respectively.
Not long after the CUHK girl left, I was summoned. There were two panelists, both seemed to be Hong-Kongers. Questions are mainly from the professor on the right side, asked whiling reading my application materials (mostly my transcripts), and the other only made brief comments. They first asked what is an "Applied Economics" program (which is what my undergrad program is called), and the difference from a normal "Economics" program. I told them that there should be little difference, and in fact many programs in HKBU has this unnecessary "Applied" in their titles. They then inquired about whether we have a three or four year program, and why the first year (Foundation Year) doest no appear on my transcripts. I replied that the Foundation Year did not count toward my GPA. They also asked why some courses on my transcripts do not have a grade (those are courses that I am exempted from), and whether I had a minor (Math). Lastly they asked why the Real Analysis course in only a 2000 course in HKBU, while in CUHK it's a 4000 course. I replied that I wondered the same thing and in fact Real Analysis is probably the most difficult in the whole undergraduate math curriculum. At the end I asked them how many students were invited to this interview and when I would be informed of the result, and got 40 students and within one to two weeks as the answers.
Generally my previous worries about technical questions proved to be unneeded. They only cleared some concerns they had with my transcripts, and the questions are in fact mostly to my advantage. I left CUHK with confidence, given that this MPhil program recruits nearly twenty students each year, and despite they might interview other students separately (say in Shenzhen), but overall since there must be students who decline their offer eventually, the odds of getting admitted are very high to those interviewed. The interview seemed only a "sanity test", or a final double-check before extending their olive branch.