How hard is it to calculate the probability of humanity communicating with other civilisations?
Dr Frank Drake’s Equation is one attempt to find an answer.
Possibly the most interesting factor is "L", the time a civilization might spend indicating its presence.
This can be inferred by looking not at the stars, but ourselves.
The longer that humanity succeeds in not annihilating itself and continuing to broadcast detectable signals, the longer we can guess other civilizations will do the same.
More recently, Dr Claudio Maccone has tried to add numbers to the Drake Equation.