National borders are artificial constructs. There is no reason to differentiate between trading with someone across the street or on the other side of the globe. Geographic monopolies (AKA “states”) subject “their” citizens to trade among themselves. As a result of these limited economies of scale, competition is proportionately reduced, leading to higher prices and reduced quality for the goods and services involved.

Reducing these barriers would immediately result in lower prices, lower costs of production, increased availability of goods and services, and increased product quality owing to a vastly greater menu of consumer choices.