Witold Rybczinski ("Ask the people") has his doubts abou the value of "public participation" and "public input". He is writing about the design process, but it is a view worth considering. What do we know? (1) Who shows up at hearings? Who is "the public"? How representative are such folks? The answers are pretty clear. In fact, public choice economics suggests that when participation is invited, interests with a strong stake will mobilize first; and (2) Talk is cheap.
From Rybczinski's post: "Speaking recently at a British conference on urbanism, Daniel Libeskind called for a greater degree of public participation in the design process. 'The people have to be empowered to be involved in shaping the program, not just the program but also the actual space, he said. Let the voice of the people be heard!"
These are simple points. But when I cite market tests and how they vet worthy vs. unworthy projects, I am often reminded that there are analogous opportunities outside the market. These are elections and other channels of public participation. Democracy has its well known problems, as does "public participation".
I have blogged before about a plausible division of labor. At most scales error correction is possible (although never trivial). This is critical for better resource allocations. But at large enough scales, error correction becomes almost impossible. These are the mega-projects. In those cases, soothing evocations of public participation are not nearly enough and we have to live with the mistakes.
ADDED
From a more recent WR blog post: “'I want my architect to have already made all his mistakes,” a developer friend once told me." I had not heard it put this way before.