What kind of leadership is most effective? The answer to that question is probably one of the most written on topics in the history of business. Based on both my education and personal experiences, I believe that an appropriate leadership style is truly dictated by the situation. This is hard for many to understand since contingency leadership is strictly dependent upon the situation, person, etc.; There truly is not one style of leadership that works in all situations.
During my career in the Navy, I've had the opportunity to work with every branch of the military. In those experiences, I have found that if you're a Marine charging a hill and being fired upon, the type of leadership to use is much different than sitting on a ship launching cruise missiles. The Marine charging a hill cannot question his leadership and must comply strictly with the orders given to them; this explains why the Marines are much more directive in their leadership style. You do not have time when bullets are flying to collaborate and seek input. On the other hand, if you're on the ship, there is much more opportunity and time to decide on the proper approach and process to use. For this reason, leadership styles vary from military branch, unit, and specialty. Based on this analogy, you can see that leadership is dictated by the situation you're in and the people you are leading.
So, when I am asked the question of what leadership is most effective, I use this model and say that the best leadership is one that matches the situation and caters to the people involved. The problem with this strategy of leadership style used is that from the outside, it may not appear as transparent and fair since you are matching the situation and/or people to optimize the outcome. When I taught at a university, I had one gentleman seeking counseling for post-traumatic stress disorder; because of this situation, he was unable to attend classes on a regular basis and missed 8 out of 32 scheduled classes. Other students looked at the situation and did not understand why I allowed this gentleman to pass the class given the large amount of time he missed in the classroom; they did not know about his situation in seeking counseling for PTSD. Due to this, other students felt there was a failure in leadership (since it was perceived that this student was being treated more favorably than other students when the reality was being fair meant considering the situation and the person involved).
This was a tough situation given the fact you cannot divulge certain information due to privacy issues. However, you also want to make sure people are aware that there's a reason and rationale for the way you are leading this person.
So, the answer to this question of what is most effective leadership is one that considers the situation and the people involved. Once you assess this, applying the appropriate leadership style is where most people mess up. Failure in leadership comes from the inability to apply the correct style in the correct context. In addition, as leaders, we also fail in that we need to make sure that the team we are leading understands that there's a reason and rationale behind your actions, despite your inability to be transparent. I find that the answer to this question lies in the exposure you have to leaders that have been successful and yet have had failures.
My interaction with senior leaders within companies like Messer, Louisville Paving, Hussung Mechanical, and several others have shown me that successful companies are ones that understand the link between circumstances and leadership.