I read a meta analysis from « The leadership Quarterly » about How bad are the effects of bad Leadership? A meta-analysis of destructive leadership and its outcomes. The authors focused on the behavior of the leader directed toward its followers. They defined bad leadership in order to narrow down their meta-analysis. Some behavior are that they listed are: abusive supervision, destructive leadership, toxic leadership and petty tyranny. Bad leadership can be perceived by the followers or sensed as the intent of the leader to negatively or positively affect their followers by their actions. A leader making a favor to one of its follower can be seen as a negative intent for those not receiving it. Violence is also mentioned as it can be verbal and physical. We have to keep in mind that physical violence may not happen so often in the work place (at least I hope). Bad leadership in this study is also defined as a repetitive behavior  over a long period of time. He behavior cannot be defined as bad as long as the leader does not constantly use this behavior.
The most cited leadership behavior in all studies was abusive supervision but the ones in the list below were also mentioned. They were used to determine if there is a link between bad leadership behavior and the behavior of followers.
List of bad leadership behavior:

Such behaviors when repetitive are not acceptable because we assume that they undermine the followers capacity to focus on delivering high quality services or products. They should be respected. The meta analysis proved that this assumption was right. Bad leadership leads followers to perfom at a lower level. They show the following reactions:

All those behaviors reduce productivity because the employees are not focusing on performing their job but on “surviving” , trying to avoid implication or trying to go away. All that if not handled in time can damage your company existence. The question should not be “why are those employees results so bad?” but more “what are we doing wrong as managers?”
Is there in your company a bossy boss causing so much trouble that the turn over, sick days and so on are so high that you wonder if you will get some work done? If yes, what should you do? Your bossy boss is probably not that bad technically. Otherwise, he would not have been promoted. He may not know that his behavior impacts the team that much. He may even think that he is the best boss ever because people respect him. He just does not see that people fear him more than respect him.
One good way to deal with bossy boss is to evaluate them to understand what kind of behavior they express the most. Here is why 360 Degree test exist. It is to make people aware of their impact and how they are perceived. It helps them to focus on what they could do better not what they did wrong. Amazingly we prefer to look at the glass half full than half empty when we look at our dark side.
Bad leadership is damaging companies by diminishing the most precious capital they have, their employees. It impacts the employees working directly under the leader behaving badly. If you are still not convinced that bad leadership behavior is a serious subject to deal with. I invite you to think of a time in your life when someone used his higher position with the apparent intent to harm you. What was your first thought? How did you react? I am pretty sure you will remember experiencing some of the listed reaction above. Do not tell me now, that this did not impact the way you worked. That you were invincible. Maybe you even left the company because of this person. Bad leadership behavior is too important and impactful to be ignored.
Bad leadership behavior should be identified and dealt with. There are ways to positively impact a leader so that he learns other behavior to achieve the goals he / she has set for himself / herself. It always comes back to the main question:”How do we help people change?” Here is one way (out of the many) to help people change a behavior:

You may face some of the following resistance:
  • Self depreciation: I cannot change, I am just too bad
  • Habits: I have always done it this way!
  • Fear of the unknown: What if I do not recognize myself in the end?
  • No urgency to change: Why change things are not so bad as you say

People usually change when the pain is too strong. This happen in time of crisis when the bossy boss faces a law suit, loses his job, do not get the promotion he was supposed to get.
Theory give the feeling that you can change anything but my impression is more that you can only helps someone to change when he / she is ready.