各位同學，其實大家上完econometrics係咪過一個暑假就原銀奉還？OLS以外的模型你們不懂很合理，但諸如dummy variable, heteroskedasticity與omitted variable bias都是很基本的東西。好些同學甚至連OLS coefficient及p-value的意義都不懂。

有系統地分析數據可說是經濟本科少數需要上學讀的內容，學不懂這科倒不如自行在家研讀經濟解釋，既省時又省錢。

Dear students, how much econometrics do you still remember after one summer? I know you have not learnt models other than OLS, but dummy variable, heteroskedasticity and omitted variable bias are all very basic. Many of you do not even understand the meaning behind OLS estimated coefficient and p-value.

Data analysis is one of the only few subjects in the undergraduate economics curriculum that demands studying in school to learn. You can pretty much study everything else at home by yourself.