Thanks to Francis Bula for pointing us to this article from last November which I would certainly not have seen otherwise.
The article refers to a theory that shows including public participation, what we like to call community engagement, speeds the implementation of new ideas.
Creighton’s theory compares two types of decisions: Unilateral and Public Participation. Unilateral decisions result in a quicker decision being made, but implementation time can take significantly longer because of legal issues, controversy, or other delays. Conversely, a decision made with public participation increases the amount of time it takes to make a decision, however, that time and much more is made up in the implementation process. Thus, including more voices at the table results in a more efficient and timely process compared to unilateral decisions.
They include a graph to illustrate the point:
The example they use in the article is about bike share in Los Angeles. But the theory seems to be useful for all development and planning decision making.