Shortages affect people in a variety of ways. If there is a shortage of food many people can die from starvation. If the is a shortage of water (a drought) many people can not only die but no one will be able to bathe and the animals can suffer from dehydration. On the other hand, a surplus is entirely different.
The passage describes the Author's impression of students participating in the "Upward Bound" program and it is generally favourable towards the program, without giving a more specific reason for this favourable opinion, it's more the author's personal impression.
Thus, we could say that the author has a positive bias towards the program.
