The past is a shadow, always following, but never catching up.
Natural experiments can provide valuable insights into economic questions.
要是我梦见你爱我，你休怪，休要迁怒于睡眠；你的爱只在梦乡存在，醒来，我空余泪眼。
预防金融危机的最佳方法是在经济景气时期建立强大的资本缓冲。