Based on many questions about a potential employee disclosing their salary history, I'm under the impression this is common and a little undesirable.

Would this practice be a little more equitable if the employer disclosed salaries of past employees at this or a similar positions within the company? It could be considered a privacy issue (Especially if only one person ever held that position.), but my guess most employers don't feel obligated.

Does it seem fair to ask what were the previous or current salaries for a similar job when asked to disclose salary histories during the interview process?