1 It seems to (at least under certain conditions) reduce the incentives of states to declare war, and thus reduces the massive wealth destruction that comes with inter-state war.
2 It allows new (productivity-enhancing) technologies and practices to spread faster.
3 It enlarges the potential market on which novel products may be sold, and thus improves the expected ROI from investments in technology/ product development.
4 Positive network externalities (e.g., the value I get from my personal smartphone increases as a function of the total number of worldwide smartphone users).
Some further magical powers of trade:
1 It seems to (at least under certain conditions) reduce the incentives of states to declare war, and thus reduces the massive wealth destruction that comes with inter-state war.
2 It allows new (productivity-enhancing) technologies and practices to spread faster.
3 It enlarges the potential market on which novel products may be sold, and thus improves the expected ROI from investments in technology/ product development.
4 Positive network externalities (e.g., the value I get from my personal smartphone increases as a function of the total number of worldwide smartphone users).