I'm skeptical when people claim that their lack of managers mean they don't have a hierarchy. If there isn't an official hierarchy there will still be an unofficial one in some way - founders and early employees with more esteem/authority, etc.
Authority, however, is totally different. It's the power to make someone do something they don't want to, and we try our darnedest to avoid that kind of situation. (Also note that "having authority" is different from "being authoritative".)