  The Drake Equation has proven fertile ground for speculation about the
abundance, or lack thereof, of communicating extraterrestrial intelligences
(CETIs) for decades. It has been augmented by subsequent authors to include
random variables in order to understand its probabilistic behavior. However, in
most cases, the emergence and lifetime of CETIs are assumed to be independent
of each other. In this paper, we will derive several expressions that can
demonstrate how CETIs may relate to each other in technological age as well as
how the dynamics of the concurrent CETI population change under basic models of
interaction, such as the Allee Effect. By defining interaction as the change in
the expected communication lifetime with respect to the density of CETI in a
region of space, we can use models and simulation to understand how the CETI
density can promote or inhibit the longevity and overall population of
interstellar technological civilizations.
