"Randomized experiments are the gold standard for causal inference, but they are not always feasible."
世界是生者的地方,死者在其中没有位置。死者什么都不是。他们甚至不是记忆。他们被遗忘了。而生者,也将被遗忘。
The beauty of mathematics lies in its ability to describe the universe in a language that is both precise and universal.