I expect that when we have a colony on Mars, exports will be found. Either mineral deposits which are rare on earth, or manufacturing processes which are easier with lower gravity.
A human being able to lift 3x as much without machines already opens up possibilities for greater productivity.
Stuff that must happen in the cold is cheaper to do too...
Think of Vegas - no economic output at all, tourist destination alone. Mars could do the same.
It only takes one thing - there is no need for a mixed economy.
I'm skeptical of that. Mars may indeed have some small advantages over Earth in certain niches of mining or manufacturing, but it's hard to imagine how those advantages wouldn't be greatly outweighed by the added difficulty of doing... just about anything on an uninhabitable planet, and expense of shipping the final product back to earth.
My skepticism comes from a different direction. Assume there's something that can be done at lowest cost on Mars — is it cheaper to send humans to do it (with all the necessary life support, radiation protection, and the inevitable black swans because we've never done anything like this before), or to figure out how to fully automate it and send robots?
If it takes 10,000 people to make $thing, then even at Musk's target price of $100k/person, the cost to develop and ship the automation[0] only has to come in less than a billion dollars to win.
[0] I guess the TCO would be more complex to determine, as the human side includes not just paying the humans (and presumably shipping good from Earth), but also figuring out how to do low-gravity and zero-gravity healthcare and surgery (on this scale there will be emergencies requiring surgery during transit), and planning for the colonists' desire to start families and retire.
A human being able to lift 3x as much without machines already opens up possibilities for greater productivity.
Stuff that must happen in the cold is cheaper to do too...
Think of Vegas - no economic output at all, tourist destination alone. Mars could do the same.
It only takes one thing - there is no need for a mixed economy.