Why doesn't the university give past final exams' answers? My professors usually give solutions for part term tests. But it seems that, they never gave any solutions for the past final exams in any courses I've taken.

Does anyone has the same experience? Or does anyone know why it's like this? I personally believe that students could use past exam's answers to prepare for their own exams.

Edited: Wow, it's amazing that so many people shared their opinion here. I'd just like to clarify my question here cuz I see my question mislead few people, my apologize. Say, I am taking some course this year, and the professor would usually post some pasts term tests with answers and the past exams from previous years(with no answers, or sometimes they just post a link to the library website, where answer-free version of past exams can be found) on the course web-page.
This depends on the institution &amp; department and potentially the instructor/course. 

The last two institutions I have been at (UK) have provided solutions to past exams. One only odd numbered years, the other all years.

I'm sceptical about the value of providing solutions to past exams for studying purposes. From my experience the temptation to look at the solutions instead of struggling through the questions is often irresistible for students, especially those who are struggling. This leads to the false impression of knowing how to solve the problems. Of course past exam solutions can be used effectively to study, for example by only using the solutions to check answers after completing the entire exam as practice. But I have rarely seen students do this.

Developing appropriate exam questions is difficult so instructors may also want to recycle past questions and therefore not provide past exams (questions or answers).