Using The New Essential Guide to Alien Species (Del Ray, 2006), and some hard work with a calculator and yellow legal pad, here are the Drake variables as applied to the Star Wars Galaxy:
Number of stars: 400 billion
Number of stars with planets: not given, but I estimated 300 billion
Number of planets suitable for life: 200 billion
Number of planets where life arises: 20 billion
Number of worlds where intelligent life arises: 20 million
Number of worlds whose communications can be detected: The Holo-net seems to work everywhere, so I'd say all of them.
Broadcast time: For isolated civilizations, about 10,000 years. For Republic worlds, potentially forever.

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