Healthy communities can solve problems very effectively. Social conventions and unwritten rules can be more effective than enforced policy.
Here's my recent take on community solutions. Essentially, the more tighter knit a community, the more it relies on community solutions. However, the more impartial people are towards others, the more technical or legal the solutions become--relying on the "system" to manage the faceless crowd. These are correlations, not implications. I think these are part of the reason why Community May Not Scale: