At my university publishing old exams is considered a good practice.

Some advantages:

• Students know what to expect during real test.
• Students can test their knowledge and check which topics they need to relearn.
• There is an additional problem supply for practice.
• Sometimes professors lose their old tests (e.g. disk failure, etc.), and publishing them might serve as additional backup.
• You get access to exams constructed by your predecessors and your successors will get an easy access to yours.
• As pointed out by @AndrewStacy, it makes sure that everyone has access to tests and so "levels the playing field".

Some disadvantages:

• Creating a new exam requires more work.
• It might be hard to assess the difficulty of a new problem.
• New exams are harder to grade objectively.
• Students know that some areas might be more probable (e.g. theorem XYZ won't be used, because it was given last year) than others.

I hope this helps $\ddot\smile$

At my university publishing old exams is considered a good practice.

Some advantages:

• Students know what to expect during real test.
• Students can test their knowledge and check which topics they need to relearn.
• There is an additional problem supply for practice.
• Sometimes professors lose their old tests (e.g. disk failure, etc.), and publishing them might serve as additional backup.
• You get access to exams constructed by your predecessors and your successors will get an easy access to yours.
• As pointed out in the comments by Andrew Stacey, it makes sure that everyone has access to tests and so "levels the playing field".

Some disadvantages:

• Creating a new exam requires more work.
• It might be hard to assess the difficulty of a new problem.
• New exams are harder to grade objectively.
• Students know that some areas might be more probable (e.g. theorem XYZ won't be used, because it was given last year) than others.

I hope this helps $\ddot\smile$

At my university publishing old exams is considered a good practice.

Some advantages:

• Students know what to expect during real test.
• Students can test their knowledge and check which topics they need to relearn.
• There is an additional problem supply for practice.
• Sometimes professors lose their old tests (e.g. disk failure, etc.), and publishing them might serve as additional backup.
• You get access to exams constructed by your predecessors and your successors will get an easy access to yours.

Some disadvantages:

• Creating a new exam requires more work.
• It might be hard to assess the difficulty of a new problem.
• New exams are harder to grade objectively.
• Students know that some areas might be more probable (e.g. theorem XYZ won't be used, because it was given last year) than others.

I hope this helps $\ddot\smile$

At my university publishing old exams is considered a good practice.

Some advantages:

• Students know what to expect during real test.
• Students can test their knowledge and check which topics they need to relearn.
• There is an additional problem supply for practice.
• Sometimes professors lose their old tests (e.g. disk failure, etc.), and publishing them might serve as additional backup.
• You get access to exams constructed by your predecessors and your successors will get an easy access to yours.
• As pointed out by @AndrewStacy, it makes sure that everyone has access to tests and so "levels the playing field".

Some disadvantages:

• Creating a new exam requires more work.
• It might be hard to assess the difficulty of a new problem.
• New exams are harder to grade objectively.
• Students know that some areas might be more probable (e.g. theorem XYZ won't be used, because it was given last year) than others.

I hope this helps $\ddot\smile$