Science Fiction settings – Worldbuilding – Economics of your solar system

This ties into my other post,  Science Fiction settings – building the universe, solar system, planet

Pyramid of Needs

One thing you rarely see, or perhaps you may only see a little bit of it, is the economics of a star system. Human settlements do not thrive in places where the economics do not support it.  Human habitations require air, food, water, shelter, and room to exercise.

After that, they branch out to things that feed the mind and soul. But if one of the basics is missing, you can bet that’s the one that will be bothering most of the characters in your story.

Aside from that, your characters need to live in a universe that makes sense on paper to you. You may decide not to include that information in your book, but it’s useful appendix information and it ensures your world makes logical sense.

Worlds can provide three raw materials: Food crops, non-food crops, and minerals. Included in the food crops are domestic and wild animals.  It makes sense to locate a factory or processing unit close to the source for whatever it is you’re doing. Therefore, if you are refining ore, you put the refinery next to the mine.

Space won’t produce the food crops and non-food crops as much, because everything you do to make those things happen requires expenditure of labor and materials to create an environment that will survive and thrive in space. That isn’t to say you can’t do that, but if you have other options for agriculture such as a planet, you do that.

Space also provides minerals on planets, and perhaps if you have a gas giant, there may be some fuels minable from that gas giant.  The most recently proposed these days is HE3, supposedly a good little molecule for cold fusion energy.

However, in space and on planets, you can create factories and technology.  There are many advantages to creating a factory in space, mostly because micro-gravity makes economy of scale easier in some senses. (Pouring hot metal into molds is one thing I can think of that has problems in micro-gravity, but maybe there’s a way to combat that.)

Factories manufacture things. Whether robotics or humans or a hybrid are used, factories manufacture things for amusement or for work. The things may be metal, which must be worked through molding, processing, drilling, welding, brazing, and cutting.  While robots are efficient, they sometimes break when parts wear out and there’s a nice human job you probably (can’t) replace.

Once things are manufactured, you either need to move them into orbit out of a gravity well, or you manufactured them in microgravity and can congratulate yourself on not getting mired in additional expenses to get your finished widgets off the planet.  Instead, you can serenely float them over to the freighter ship.


Humans are very good at producing adequate information.  [Irony alert: Some of it is fiction.] There is also considered value in art which might not have any intrinsic value otherwise.  Art fills the spectrum from written, spoken, acting, painting, drawing, sculpting, singing, making music, and so on.  Something that doesn’t produce a valuable commodity in the sense of meeting the triangle of needs (food, shelter, etc.) may be valuable due to its impact on the human soul/brain. What are sports other than games we enjoy for the entertainment?

The arts usually spring up anywhere humans are, and organized professional arts stem from the presence of upper strata high economic status people who have the money to invest in such things.

Communicating that information from place to place is vital. How do solar systems communicate? Is there some sort of FTL system in place, or are there wormgates and black holes where buoys go back and forth, or do ships carry data packages when they travel? How about money? How do you handle that when someone is traveling from system to system, and you do not have instantaneous ability to track money being transferred?


The technology of your ships may limit their size, but consider that stuff in space doesn’t need to be streamlined, or pretty, or even attractive to the humans working in it. It could have zero outside aesthetic. It just has to work. The limitations on size you get from terrestrial limitations on ocean-going freighters or trains is eliminated in space.  Potentially, you could tow thousands of containers behind your ship, as long a you have a good way to stop all that forward inertia. In many ways, it’s like a train of containers, if you think of it. Once stuff is moving in space, it continues to move until it is stopped by something else, or it enters the gravitational pull of a sun, planet, or some other object.  Ultimately, it’s the cost of obtaining fuel that will affect shipping prices, and the shipping prices affect how much of what gets shipped where.

Shipping can be done by small shipping companies such as sole proprietors, or by consortiums, or large corporations, or governments. In recent human experience, the trend is toward large corporations buying up smaller operators and creating monopolies or something fairly close.


Investors in planetary colonization want to see a return on their investment. That means that they don’t occupy a planet for the pure pleasure of being there.  Here’s the sorts of things that would appear as planetary colonies:

Science outposts/stations – study of the planet, wildlife, geology, plants.
Military outposts


One major factor for a military is who holds the command, which is usually dictated by who holds the purse strings.  With that in mind, your military is constrained from growing bigger by how much money it costs to operate. If your military is too large and takes too much money, it undermines your economy and will cause your economy to fail. However, there is a tipping point and your military can actually prop up your economy if it’s big enough.

Example: In the 1950s, the Honduras and Nicaragua had a small air war. The economies of the two respective countries allowed them to purchase 15 year old fighter planes from the United States or other countries. One country had a dozen F4U Corsairs, and the other country had a dozen P51 Mustangs.  The resulting air battle is one of the only known situations where the two planes were pitted against each other in combat.  The economy of the two countries did not permit them to have jets or modern aircraft. They couldn’t afford it.

So, consider the economics of the Star Wars universe.  What’s the line item cost of a Death Star?  Who builds such a thing?  Does it make sense? Not very much. What do you need a Death Star for? The opposition barely has a few starships.  It makes for a good tale, but doesn’t stay propped up if you consider the sheer amount of money such a thing would require.

Social Services

Depending on the sort of government you employ, the economics of a system will include a fair bit of charity.  Charity is when a person or government gives goods or services to someone in exchange for a discounted rate or no payment at all.  Wherever humanity exists, there also exists some sort of charity.

Interest rates and inflation

This is more detailed than I have time for in a quick overview, but there are many economic theories floating around, and you can get the gist of them by doing a search on google.  You can also find some theories surrounding some economic situations that may contribute good story ideas.

For instance, a large country has a surplus of grain, so they donate that grain to a starving country. However, the starving countries’ farmers are undercut by the free grain from the large country and they thus go out of business. Later, the large country stops sending their grain surplus and the starving country has nowhere else to go.

(I believe this describes the United States’ relations with some African countries, which is simplified in this example, but you can certainly see the conflict this would introduce.)

Strange Quirks of the Rich

If you’re rich, you understand this. (And you should donate sums of money to me because you’ve obviously found this post useful, or you wouldn’t have read all the way through. Just sayin’. Send me emails.)  People who are bloviated rich do absurd and stupid things for which the rest of the universe has no answer.  It’s like they wake up one day and say, “I have a zillion bucks. I think I’ll go do something wasteful with it and make everyone scratch their heads.”  And then they do.  This isn’t carte blanche for you to start writing that into your stories, it’s saying that you can sometimes put something in there which has no explanation other than, “Bill Gates wanted that to happen.” It’s sort of like all the weird stuff you encounter in a James Bond story… it’s done purely because it’s exotic, not because it’s sensible.