Natural experiments can provide valuable insights into economic questions.

一个领导者的遗产是由他们行动的可持续性来衡量的。

"True art is not about perfection, but about authenticity and emotion."

The farmer is the only man in our economy who buys everything at retail, sells everything at wholesale, and pays the freight both ways.

There is no must in art because art is free.

智者善思己，愚者堕沉沦。