"Randomized experiments are the gold standard for causal inference, but they are not always feasible."
随机实验是因果推理的黄金标准，但它们并不总是可行的。
所有行为都是由某种形式的驱力减少所驱动的。
"Every book is a door to another world, and every reader is a traveler."
The most valuable of all talents is that of never using two words when one will do.
A writer is a person who is obsessed with language, with words, with the power of words to create worlds.
