Government is determined by 2d6-7, adding the population characteristic. The result is then referenced to a lookup table; the concept seems to be that smaller populations are more liberal, anarchistic – or less independent – while large populations require more bureaucracy and tend towards repression (which is also reflected in the Law code).
There isn’t a whole lot that can be done to create “realistic” societies with dice rolls and, consequently, I will use the Traveller table as-is unless I find fault with it later.
The governments are, according to the SRD:
Captive Government (or Colony)
Civil Service Bureaucracy
Government is probably the first thing the GM really needs to adjust to his setting. Keep in mind that there is also often more than one way to describe a government. And what a government officially calls itself does not always reflect reality; the USSR and the PRC come to mind – or the German Democratic Republic.
When the dice come up with a colony/captive world, I always look around to see what nearby powerful world (Rich, Industrialized, High Tech, and/or High Population) could be responsible. In my first sector (not the Trial Run subsector) I ended up creating a handful minor states this way.