自然实验是理解现实世界中因果关系的强大工具。
Natural experiments are a powerful tool for understanding causal relationships in the real world.
"The only way out is through."
广东话谚语
The secret of change is to focus all of your energy not on fighting the old, but on building the new.
Writing is not just about telling stories; it's about listening to the voices of the world.
唯一具有持久重要性的自由是智慧的自由，也就是说，为了本质上值得的目的而行使的观察和判断的自由。
