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Things I have learnt from customer interview

On 2021-10-20, we concluded our 11 custom interview sessions for my side project together with 2 partners. Let me quote the problem hypothesis we wrote in one of our documentations: “We believe people who are eager to improve themselves and busy do not have the time to read lengthy books

The Front and Back Door Adjustment Formula for Confounders

In fact, we have already seen the back-door adjustment when we discuss Simpson’s Paradox. We have calculated the weighted average of the rate of heart attacks with the drug in men and that in women to get the overall effect of the drug in the general population adjusted for

Simpson's Paradox

Last time, we have talked about Monty Hall Problem and Berkson’s Paradox. This time, let’s discuss another paradox called Simpson’s Paradox. Let’s consider the following table: This is not a randomized experiment. The data is observed. By looking at the data, you can observe the following:

Why do the attractive ones tend to be jerks?

In the previous post, I have talked about the Monty Hall Problem. Let’s go through a similar problem called Berkson’s Paradox/ Admission Rate Bias. In a medical study, a guy studied two groups of diseases: respiratory and bone. In the general population, about 7.5% of the people

Should You Switch Your Choice of Doors? The Month Hall Problem

I want to illustrate this problem using a causal diagram. Here is the rule of the game: Suppose you’re on a game show, and you’re given the choice of three doors. Behind one door is a car, behind the others, goats. You pick a door, say #1, and

論分工-原富（國富論）的總結

對於原富，又名國富論這本書，我斷斷續續的看了幾次，每次都沒有完成。第一次是看英文版，但古老的英文，看著實在辛苦，最後放棄了；第二次是看中文版，終於能看懂文字了，但Adam Smith實在太厲害了，看著還是吃力，也沒看完。這兩次看這本書，有感大學的經濟基本都是基於這本書的，又覺得讀經典是很有必要，所以又拿起了這本書。透過我寫總結，希望能幫助我學習。第一篇論勞動生產力改善的各種原因，並論勞動生產物分配給人民各階層的自然秩序第一章論分工這一章，我覺得是比較簡單的，Adam Smith 一上來就說，勞動生產力最大的改善都是分工的結果。你不得不佩服Adam Smith的觀察力，他以製針業的分工為例，說明如果工人獨立工作，每天能生產的針會少很多；又以農業為例子，解釋為什麼農業的工作不能完全分離出來的原因是因為農業有季節性，一個人不能只從事一種勞動，這又解釋了為什麼富國的農業未必比貧國好。分工帶來的生產力提升，主要來自三方面： * 每個人技巧的增進 * 省下轉換工作失去的時間 * 發明機器，減少勞動力

Cornfield’s inequality Causation v.s. Correlation

In the last post, I have shared about a debate: Does smoking cause lung cancer? A case on causation v.s. correlation Today, I would like to show the proof on Corenfield’s Inequality, an inequality that settled the debate. I have read the original proof on the paper. Although