
《Freakonomics》這本書聽閒是近期大熱,台譯書名《 蘋果橘子經濟學》,國內有譯《怪雞經濟學》。在網上試閱了廿多頁英文版(pdf),感覺也還可以。
Just because two things are correlated does not mean that one cause the other. A correlation simply means that a relationship exists between two factors… but it tells you nothing about the direction of that relatonship… it may be that they are noth being caused by some other factors. (edited quote)
1995年之前,大批犯罪學家、政治學者,甚至克林頓都預言,1995年美國的犯罪率會上升不少於15%,甚至可能更高。但1995的犯罪率不升反跌。於是,那些專家們就忙著去解釋這個不升反跌的現象(fact)。某些理論認為,犯罪率不升反跌的原因是90年代的經濟復甦。另外有人說是因為政府的槍械管制法例。書中兩位作者說,這些理論很合邏輯,而且有鼓勵作用。這些理論令人們相信,槍械管制法例可以有效降低犯罪率;經濟復甦可以降低犯罪率。亦即,只要犯罪率一上升,政府只管定立槍管法即可解決問題。因為,犯罪率下降的原因(reason),就是槍管法。
兩位作者說,這些理論很logic,唯一的問題是﹕ “they weren’t true.”
很多時候,問題不在於合唔合邏輯。合邏輯不等於正確。經濟學家叫你唔好質疑「人是自利的」的假設,然後他們就base on這個假設開始推論。那些推論都合邏輯,唯一的問題可能就是﹕ “they weren’t true.”
如果這些東西 “weren’t true”,無法甚或錯誤地描繪事實,它們就只能是一個遊戲(game)。經濟學是一個遊戲,雖然在這個遊戲之下有很多受害者。像大屠殺,大屠殺也是一個遊戲,只不過,輸左就真係會死,係有consequence架。
誤認因果,後果可以是﹕
Consider the folktale of the czar who learned that the most disease-ridden province in his empire was also the province with most doctors. His solution? He promptly ordered all the doctors shot dead.
The conventional wisdom is often wrong.
「認知價值觀經常是錯的。」是我看到的最後一句。
Drinking eight glasses of water a day has never actually been shown to do a thing for your health.
作者之所以說日飲八杯水對健康毫無幫助,是因為他手頭上有統計數據。統計數據顯示飲八杯水與健康並無直接因果關係,並不代表日飲八杯水對於我的健康而言毫無幫助。
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作者提醒我們,經濟學最古老的始祖之一阿當史密斯, 是個重道德的哲學家。
It is worth remembering that Adam Smith, the founder of classical economics, was first and foremost a philosopher. He strove to be a moralist and, in doing so, became an economist.
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B:乖乖地行開書局買返本hard copy啦
我: 洗鬼你講