These groups use the youths to protect illegal activities like gambling, Mr. Chin said.
"Economic theory isn't always right," Mr. Chin, the information minister, said in an interview.
Mr. Chin said the killer might have wanted to burn the body to destroy evidence.
The more analytical a student's profession, the greater the chance he or she will have trouble riding, Mr. Chin said.
In the past few years, Mr. Chin said, the number of students has fallen to about 80 or 90 a year from 150.
"There must be 5,000 people who were living in that building," Mr. Chin said.
The sandwich business developed gradually, Mr. Chin said, until it all but took over.
Mr. Chin said he hopes to build a prototype by 2006.
"These kids have a certain amount of business acumen," Mr. Chin said.
"Let's just say that you develop a thick skin and a sense of humor," Mr. Chin said.