| I think you are missing the key ingredient in the analysis. The Economist is attempting to build such an oracle via statistical regression. HOWEVER, the Oracle is intentionally limited in input to a specific list of things: SAT scores, sex ratio, race breakdown, size, public or private, earning power in the city where it is located, etc. The things that are omitted constitute the actual value the University brings to the table: quality of teachers, instruction, organizations on campus, etc. (1) So however far off the model is for two given Universities must be explained by all the missing inputs, i.e. largely how "good" the University is. If the Oracle was able to perfectly predict your earning power given that limited set of inputs, then it would basically mean that a University is completely defined by SAT scores of students, sex ratio, race, etc. and there's absolutely no value they add or subtract beyond that. That was be a very, very interesting result. But you can see why it's unlikely. Hopefully this makes sense? (1) Of course it's possible that there are factors like "how many trees on campus" or "how many vowels are in the name" which might also affect earnings. But we can probably agree that it's less likely to be important than the aforementioned ones ("quality of instruction", etc.). |