Which of these would you consider a better management - an effective management or a fair management?

combination of firm fair approach will elad to effective management

It depends. A mix of both is always healthy. At times you need to be fair and at times you need to be Effective. But being effective does not mean that Management should forget the basics of Integrity and Ethics. At times its a dilemma for the Management to come out of a situation where "Means justify Ends" or "Ends Justify Means" and proper thought needs to be given before making any decision.

In my opinion management can be only effective in long run only when it is fair.

Unfairness can be effective, only when we intend to run the organization for a very short period and have no stake in reputation and trust.