Answer:
The "white speck whose sound ha[s] disturbed" Old Musoni's work is an airplane.
Explanation:
At the beginning of the short story "The Setting Sun and the Rolling World," the character Old Musoni is working on his land, tilling the soil. However, the sound of a "white speck" distracts him. He looks up and sees the white speck quickly disappearing over the rim of the sky. We can already assume it is something of great speed, which can also produce noise loud enough to be heard by the man and to distract him. As the story proceeds, the identity of the white speck is made even clearer when it is described as a "white metal bird." The white speck was an airplane, whose sound reached Old Musoni in time for him to see it disappearing over the horizon.
This is the simplest yardstick of economic performance. If one person, firm or country can produce more of something with the same amount of effort and resources, they have an absolute advantage over other producers. Being the best at something does not mean that doing that thing is the best way to use your scarce economic resources. The question of what to specialise in--and how to maximise the benefits from international trade--is best decided according to comparative advantage. Both absolute and comparative advantage may change significantly over time.
Adaptive expectations
A theory of how people form their views about the future that assumes they do so using past trends and the errors in their own earlier predictions. Contrast with rational expectations.
Adverse selection
When you do business with people you would be better off avoiding. This is one of two main sorts of market failure often associated with insurance.
