Half as many people will not support half as many enterprises In a given geographical territory, half as many people will not support half as many such enterprises spaced at twice the distance. When distance inconvenience sets in, the small, the various and the personal wither away. Jane Jacobs, The Death and Life of Great American Cities densitydistancegeographybusinesseconomics
We are surrounded by ghosts An Article by David R. MacIver notebook.drmaciver.com I'd like to call the more general phenomenon that this is a specific instance of "ghost knowledge": It is knowledge that is present somewhere in the epistemic community, and is perhaps readily accessible to some central member of that community, but it is not really written down anywhere and it's not clear how to access it. Roughly what makes something ghost knowledge is two things: It is readily discoverable if you have trusted access to expert members of the community. It is almost completely inaccessible if you are not. In this sense, most knowledge is ghost, particularly if you take an expansive view of what counts as an epistemic community. knowledge