We can never actually reach the production frontier, the vertical line theory just a easy get away for those economists. It is a joke in my personal view on it. The same kind of questions which I used to put forward to Prof. Tim Jackinson, what he said was, the assumptions are made at first place and it is not a big deal.
However, we should always remember that all the Macroeconomics theories are from data rather than which school's views. Because there is no "full-time" rational consumers on earth, everything should be taking in general terms (the ideal terms for them).
We can see that you have already built a soild fundation for economics study, I would like to say that if you really want to become one of the economists, please do not consider yourself into any those models. Just put yourself in the scenario in which all of the consumers and producers as robots and, you are spying on them from heaven, also play them as your own toys. I think you will feel better sooner or later.
After all, they are all making fun on us, since we are trying ourselves hardest to believe what they said. (thanks God, most of the famours ones are all dead).
Regards,
[此贴子已经被作者于2005-5-14 12:49:15编辑过]