This is a quote from the awesome book The Principles of Product Development Flow:

Whenever I am told that management makes decisions too slowly, I ask to see the specific proposal that went to management. Invariably, I find that the cost and the benefit of the decision are either unquantified or poorly quantified. In my experience, most managers make amazingly fast decisions when they are presented with compelling economic arguments.

There is not much I can add to this: if you want to get someone to make a decision, supply data that resonates with them, not you.