What are the economic pros and cons of colonizing a low gravity world vs a high gravity one?

This is the sister topic to this question: What are the military pros and cons of colonizing a low gravity world vs a high gravity one?

The specific question being asked here is, what specific economic pros and cons are there between a high gravity world and a low gravity one?

Longterm health effects of switching between various gravities are being ignored for this question.

• Possible duplicate of What are the military pros and cons of a low gravity world vs a high gravity one? Apr 12, 2018 at 18:31
• Trampoline-related safety gear would cost more, as it must cover a greater area. Apr 12, 2018 at 19:30
• @Renan, Asking economic vs. military is distinctly two different questions and I'm grateful that Raznarok is splitting things up. I wish more people would do this.
– JBH
Apr 12, 2018 at 21:16
• @JBH Thanks for supporting my question. I'm currently trying to get the other question removed from hold, as several of the votes about the question being too broad were already cast before I split it into two. Apr 12, 2018 at 21:20
• By "low gravity world vs. high gravity one" do you mean 1 G vs. several Gs or microgravity vs. 1 G or microgravity vs. several Gs? Apr 13, 2018 at 10:47

Overall, the differences in economics between low and high gravity worlds probably isn't significant. Low gravity would probably be better only because it makes things simpler, but high gravity has its uses.

Benefits of Low Gravity

Nearly all fuel needs are lower: Lighter vehicles use less fuel as they need to generate less force to move themselves, so pretty much all transportation costs will be lower. However, lifting stuff off-planet may not be cheaper if it has an Earth-like atmosphere: in order to achieve the same atmospheric pressure at sea level you need a larger mass of gas, which means a larger amount of gas to push through to get to space.

Larger volumes of stuff can be moved: If a mine's elevator can lift 10 tons of stuff on Earth, it can lift 12.5 tons on a world with 0.75g. If a truck can transport 10 tons on Earth, it can now transport 12.5 tons. This means that fewer shipments are needed to transport the same amount of material, which means fewer chances of accidents and lost shipments.

Safer: Falling contributes to about 1/6 of workplace related deaths. With lower gravity, the height needed for a deadly fall increases, and the amount of time a person has to grab onto something to save themselves increases. You could also save a few bucks on hard-hat material due to less dangerous falling objects.

Vertical Construction: Weight of the building, and the ground beneath it, and wind are the two major considerations in skyscraper design. Although wind will likely be similar on a low-gravity world, less gravity means less material needed to support a building. This means buildings can be taller and slimmer, as less material is devoted to supporting its own weight.

Benefits of High Gravity

Hydropower: The amount of energy that a hydroelectric dam can produce depends entirely on the pressure of water behind it. More gravity means more pressure, and more pressure means smaller bodies of water are needed to produce the same electricity. About 16% of Earth's power is hydroelectric, so a high-gravity planet could certainly benefit from cheap hydropower.

Valuable stuff: More gravity likely means a planet with a hotter and more pressurized core. More temperature and pressure means more volcanic activity, which will lead to more layers of igneous rock. More igneous rock will mean a variety of valuable stuff is common, such as platinum, chromium, and diamonds.

More funiculars: Some mines used gravity powered funiculars to get material down hills, as the heavy, loaded, descending carts were used to pull up light, unloaded, ascending carts. Not economically important, I just like the word funicular.

Reduced fuel usage

This applies to nearly any non-organic mechanical system. With lower gravity, the amount of force required to lift anything is drastically reduced, thus requiring less energy to lift it, and thus less fuel to generate that energy.

The immediately obvious application is rocket launches. The space shuttle used half a million Kg of highly-volatile solid fuel just in the first minute-and-a-half of its flight (source) which would be drastically reduced in a lower-G environment. Most of the fuel requirements for a rocket launch come from the first handful of minutes, during which the rocket has to physically get away from the planets surface, but also accelerate to orbital velocity. Lower surface gravity translates to a lower orbital velocity, which translates to less energy required to get there.

But wait, there's more!

A less obvious advantage is...every other machine! Construction equipment would have to exert less force to lift heavy loads. Ground vehicles would have less friction between the wheels and the road which, while admittedly causing other problems, would also mean they need less energy to move. Atmospheric craft would be able to be larger and use less fuel.

Beyond the primary economic benefit of just having to spend less money importing whatever fuel source your colony uses, this would translate to more efficient (and therefore cheaper) transportation overall. Transportation and logistics was a 1.48 Trillion USD industry in 2015, in the USA alone. Moving stuff from where we have it to where we need it is simultaneously one of the most expensive and most necessary parts of an industrial society.

Looking at just the economics, a lower-G planet lets you move more stuff with less work and for less money.

• Very strong points in favor of Low, but are there any industrial processes you can think of that would benefit from a higher gravity planet that you can add to your answer? Apr 12, 2018 at 16:45
• @Raznarok the unfortunate truth is that there are enough processes that would benefit from both lower and higher gravity to make that a net neutral comparison between them. The only economic benefit I can think of for a high-G world is that it may have higher levels of rare earth metals and volcanic activity Apr 12, 2018 at 17:26
• @enpaul I disagree that there would be a net neutral comparison - as you state in your answer there are far more, more costly processes that would benefit from low gravity than there are ones that would benefit from high gravity. Apr 12, 2018 at 17:55

Buildings would have to worry about gravity less, so you could have towers that lean more so they have more rooms but not be as high because winds get stronger as they get higher as covered in a previous comment.

Trampolines as transportation systems if the gravity is low enough! You could set them up along roads and boing along them to your destination with little effort. It would suck if you missed the next one though...

Also, I don't know whether this is important but digging would be made easier. The stuff you are digging through would be less compact so lighter and you need to move less weight to go the same distance down. Also, it would take less energy to move the stuff out of the hole because of the lower gravity. Maybe this would make buildings cheaper because foundations are easier to dig?