Since Nassim Taleb coined black swan as an event that occurred as a complete surprise for everybody, the metaphor of the black swan has been applied to a much wider variety of events. Black swan events now comprise events that are a surprise for some but not for others, events that have a low likelihood, events that were not believed to be possible but still proved to be possible, events that were dismissed as being too improbable to worry about but happened anyway. For a decision maker the black swan problem is choosing where to put effort to prevent, or mitigate events for which there are warnings, or for which the possibility has been put forward. Does the fact that there are thousands of books written about fire breathing dragons warrant the development of an Anti-Dragon Defense Shield? The black swan may have been a surprise for Willem de Vlamingh in 1697, it was not a surprise for the inhabitants of Australia, for which the appearance of tall white humans was their "black swan event". In this paper we explore the options available to decision makers when confronted with the various sorts of swan (or dragon) events.

中文翻译：

---

龙，黑天鹅和决定。

自从纳西姆·塔莱布（Nassim Taleb）创造了黑天鹅作为一个让所有人都大吃一惊的事件以来，黑天鹅的隐喻已被应用到各种各样的事件中。黑天鹅事件现在包括使某些人感到惊讶但对其他人来说并不令人惊讶的事件，可能性很小的事件，被认为不可能但仍被证明是可能的事件，被认为太不可能而不必担心的事件但还是发生了 对于决策者来说，黑天鹅的问题是选择在哪里努力防止或减轻有警告或已提出可能的事件。有成千上万本有关喷火龙的书籍的事实是否值得反龙防御盾的发展？对于1697年的威廉·德·弗拉明格（Willem de Vlamingh）来说，黑天鹅可能是一个惊喜，对于澳大利亚居民来说，这并不奇怪，因为高个子的白人出现是他们的“黑天鹅事件”。在本文中，我们探讨了决策者在面对各种天鹅（或龙）事件时可以使用的选项。