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
highdensityandovercrowding They hated both equally, in any case, and coupled them like ham and eggs, so that to this day housers and planners pop out the phrase as if it were one word, “highdensityandovercrowding.” Jane Jacobs, The Death and Life of Great American Cities densityurbanism
The technology shelf Motorola developed what it called a 'technology shelf', created by a small group of engineers, on which were placed possible technical solutions that other teams might use in the future; rather than trying to solve the problem outright, it developed tools whose immediate value was not clear. Richard Sennett, The Craftsman The Usefulness of Useless Knowledge problemstechnology