You need to be creative to develop the scant vegetation and the available resources. By fishing at Lake Titicaca, mining ore in the mountains, breeding alpacas, and actively trading local goods, the inhabitants generate continually grow in wealth.
The inhabitant who best uses his potential will have the highest yield in the end!
New production sites are built, orders are fulfilled, and goods are stored for hard times. And road construction should not be neglected either, as that is needed to speed up development.