[求助]请用微观经济学原理解答该问题

Since the person (鲁人) chose to work at a foreign county,it indicates that his productivity is worth more there. Part of his earnings may also be sent back to 鲁 for increaing the welfare in the country.

There are two reasons why Confucius blamed him. First, by bringing him back the overall earning decreases (鲁 pays less). Second, the opportunity cost (the buying price) is hidden and therefore economic cost can not be calculated correctly.

Overall, the welfare in both countries decreases.

以下是引用waterhorse在2008-4-24 1:23:00的发言：Since the person (鲁人) chose to work at a foreign county,it indicates that his productivity is worth more there.

It's a free choice?

类似于限价供给导致的市场失灵