我的研究從小小的島開始

板主回覆:
One country 是因為：

不喜歡nationalism，不喜歡各個國家各擁武力。最好有個世界政府、世界軍隊。

另外，一些交易成本是不必要的，例如不同的貨幣等等。

Decentralized governance還是必要的。因為：

容許不同制度的競爭。容許因地制宜的便利。

板主回覆:
Sorry, I cannot type Mandarin now.

But, it is an empirical fact that people take less time in
commuting than before. Whether that's because of highway or not
may be a different question. But, with a highly developed road
network, people certainly have, on average, faster way to connect any two points.