The other factor I imagine is proximity/availability of raw resources, and refineries of raw resources: if you're not shipping those shoes across the world, you still have to transport the plastic, leather, rubber etc to make them.
- Location selected based on cost of labor.
- Major port is developed to deal with large amounts of goods
- A few more factories/industries start in same area due to port accessibility
- Refineries are built to be close to location of usage (now they import raw materials instead of refined materials)
- More factories are built due to easy availability of resources + accessible port for export
- Labor gets more expensive, but economies of scale of factories + refineries means it is cheaper to stay in place then to move elsewhere
- Automation slowly displaces labour.
As a thought experiment if there was a magical 3d printer that could take any number of raw materials as inputs and combine them in any way would it become more efficient to ship a mix of raw materials to each end consumer? Say I consume x amount of rubber, y amount of cotton, z amount of plastic, etc in my consumer goods in a day, week, month whatever. Could it be more efficient to get the rubber and cotton to my door and run them through the printer than it would to build the shoes, basketballs and t-shirts somewhere else and ship them?
It's a bit like Blue Apron etc; you pay a small premium for the theatre of doing the assembly step yourself.
Proximity to resources is priced in to 'cost', no?