The Theory of Interstellar Trade (1978)

Any discussion of interstellar trade deserves a mention of the fantastic Charles Stross book "Neptune's Brood". I went into it expecting more or less a sequel to "Saturn's Children" but what I got was a treatise on monetary policy for economies that span multiple star systems. The concept of slow and fast money and its implications is utterly fascinating and the book is worth reading just for its explorations of the topic (the plot isn't too bad either). A quick…

Abstract: > This paper extends interplanetary trade to an interstellar setting. It is chiefly concerned with the following question: How should interest on goods in tranist be computed when the goods travel at close to the speed of light? This is a problem because the time taken in transit will appear less to an observer travelling with the goods than to a stationary observer. A solution is derived from economic theory, and two useless but true theorems are proved.

Any civilization that has mastered interstellar travel will almost certainly also have mastered atomic transmutation as well. So as long as all the interesting stuff is made of atoms, and the atoms over there are the same as the ones over here (which AFAWCT they are), there are only two possible "goods" that could be worth transporting between star systems: information, and free (in the physical, not the economic sense) energy. You don't need a space ship to transfer either…