Could an entire galaxy spanning government be able to maintain an universal basic income?
About as likely (or unlikely) as it is for an entire planet, or an entire country.
- You would need a tax base to pay for it. This is proportional to the population size, not the number of planets.
- You need an administration. Again this is proportional to the population size.
- There might be problems when the cost of living differs strongly between planets (garden planet, desert world, ...). No different from the problems with a basic income when some recipients live in high-rent districts and others live in run-down neighbourhoods.
While it doesn't seem noticeable than basic income is applied in the Star Wars universe. However, if a galaxy-spanning civilization has communications system fast enough to keep up with the movement and transportation of its citizens. This might be easier to achieve in a relativistic universe where communications is at lightspeed and travel is sublight than a universe where faster-than-light travel and communications is the norm.
What makes this kind of distribution of wealth possible is a combination of computer networks and the algorithms to ensure the allocation of basic income to its citizens. This might be as simple as if you are a citizen of the galaxy-spanning civilization you will receive your allocated quantum of income. But it is not unreasonable to presume that a galactic civilization will have a better understanding of economics that their basic income algorithms will be based on that improved knowledge.
A discussion of the pros and cons of basic income can be found here. It is introduced by the following remarks which indicate that most institutions it will have its positive and negative outcomes.
Should everyone receive an income from the government regardless of wealth?
The concept of a universal basic income is currently being explored by several European governments, gaining supporters on both the Left and the Right.
Funded from the public purse, the no-strings attached minimum payment is designed to guarantee against poverty.
Every citizen would be entitled to receive it, but would it actually work as a way of reforming social welfare?
Or, would it simply lead to greater long-term inequality?
There is no such thing as a universal panacea. But we can hope there will be small improvements.