Because I am lazy ....
I am a firm believer that decision-making should be dissolved to the lowest level possible. This stems from my management philosophy that (unnecessary) centralized decision-making creates choke points that slow down efficiency and effectiveness.
I often hear excuses from fellow leaders that their middle managers (MM) are not able, or willing, to make decisions. To me, equipping MMs with the ability and confidence to make the right decision does not happen by chance. It is a deliberate process. If their MMs are not able or willing, it is their fault as leaders.
I personally use a three-stage approach that has worked well for me:
In Stage 1, whenever my MMs come to me with a problem, I give them the solution explaining my thinking. In Stage 2, after I have helped my MMs solve problems for a while, I then tell them not to come to me with problems but also to come to me with what they think are the solutions. Here, I help them decide on what to do explaining my thinking behind the decision. In Stage 3, when my MMs come to me with a problem and a solution, I tell them "why come to me"? You know the problem, you have the solution, and you already know my thinking, just go ahead and solve the problem.
As a leader, my role is not to create more followers but to create more leaders. And when I have more leaders working with me, I have more capacity to solve tomorrow's problems.
Sorry, I am just lazy this way.
