  Geographical distributions, ages and sizes of astronomy-related organizations
have been investigated from comprehensive and up-to-date samples extracted from
the master files for StarGuides/StarWorlds. Results for professional
institutions, associations, planetariums, and public observatories are
commented, as well as specific distributions for astronomy-related publishers
and commercial-software producers.
  The highly uneven general pattern displayed by geographical distributions is
still very much the same as it was at the beginning of the XXth century, even
if the densities are higher -- another illustration of the well-known
socio-economic effect of self-reinforcement. Other geographical peculiarities
(local concentrations, national cultures and policies, electronic astronomy,
..) are discussed in the paper, as well as the uneasy separation between
amateur and professional astronomers in associations.
  Some events had a clear impact on the rate of foundation of astronomy-related
organizations, such as World Wars I and II, the beginning of space exploration,
the landing of man on the Moon, the end of the Cold War, spectacular comets,
and so on. However, as detailed in the paper, not all of them affected in the
same way Western Europe and North America, nor the various types of
organizations.
  The size of the vast majority of astronomy-related organizations is
relatively small, with again some differences between Western Europe and North
America.
