挑战不仅仅是给人们钱，而是要理解他们在约束下如何做决策。
The challenge is not just to give people money but to understand how they make decisions under constraints.
The wall is the oldest and most revolutionary architectural element.
Sometimes the questions are complicated and the answers are simple.
实验中的精确性和假设中的创造性同样重要。
"The world is a book, and those who do not travel read only one page."