Category Archives: Political Economy

由於颶風哈維造成大量破壞,市場認為美國聯邦政府會較預期早耗盡國庫,導致美國國債短期息率飆升,並出現罕見的 U型息率曲線。

事實上,美國債息自兩年前開始就一直上升。從下圖可見,現時的短期息率和兩年前同期相比高了超過一厘。息口上升只限十年以內國債,也許是市場對現屆政府的穩定感到憂慮?

Did you know that one of the pioneers in neural network was an econometrician? This was not an easy book to find, but it was well worth it. The book is a collection of articles written by Halbert White—as in *White* Standard Errors—that rigorously laid the theoretical foundation for the effectiveness of neural nets, including universal approximation, consistency and asymptotic normality of learned parameters. These results fill a much-needed gap for those with a background in statistics.

社評﹕AI革命席捲全球 政府須積極回應 – 20170901 – 社評 – 社評 – 明報新聞網

「人工智能」是今年最熱的議題,人云亦云的情況和三兩年前「大數據」不遑多讓。香港的「AI教育」其實不差:很多中小學都有Lego機械人隊。問題是學生無論多喜歡製作機械人,最終選擇以數據科學作為職業的數目相當少。這一來是因為香港的大學學位分配由政府主導,二來過去二十多年來政商界對科技的不重視,已經使香港的高科技產業遠遠落後週邊地區。
以香港科技積弱的程度,我相信新加坡和深圳一點都不擔心來自香港的競爭。當社會情況每況愈下,香港最大的優勢恐怕快要剩下作為走資港的地步了。

 

《金融時報》提及我以深度學習—依家興叫「人工智能」—估計車牌拍賣價錢的研究。
My deep learning paper on predicting license plate auction prices made it to Financial Times! This is actually the first paper in a series: followup papers will use the prediction model to look into various investment anomalies. Somewhere down the road there will also be a field experiment where we will provide auction participants with an app to gives them estimates in real time.

(Thanks to James Ko for sending me the article!)

 

特朗普與689

在網上見到有不少本土言論對特朗普的作風大表認同,認為是對左翼人仕的打擊。 我覺得這是十分奇怪的看法 。
 
特朗普由參選開始已經謊話連篇,政策民粹至上。上任後不顧利益衝突,政策閉門造車,用人唯親—最新消息是他從國家安全委員會裏免去三參軍參謀長及國家情報局長,只留下一眾親信—還起用了一個不知所謂的發言人。有沒有覺得這樣似曾相識?這分明就是美版689。
 
在特朗普當選之前我跟我的美國朋友說。我們香港過去五年所經歷的,你們也要經歷。結果特朗普比689更厲害:還不到一星期就已經把美國的政治道德底線推至歷史新低,更不用說美國總統的一個決定就可以讓無數人家破人亡。
 
有人會說特朗普是民選出來的,管治完全合法。這個說法沒錯,不過689的管治也是完全合法,又不見得大家覺得應該乖乖就範。而說到民意支持,美國和香港一樣也是用間選,特朗普和689一樣都沒有大多數市民的支持。689在上任之初,還受不少港人歡迎呢!
 
在今次移民禁令事件中的另一個觀察,是舉世的執法機關基本上都是唯命是從。在上位者的要求,前線人員基本上都會執行。如果說美國人民應該接受特朗普的政令,那香港市民亦都一樣。如果這樣,大量於去年被捕、受迫害的年輕人,又有誰為他們伸張正義?

Pay for the Wall with Tariff

The rumor is that Trump is going to slap a steep tariff on Mexican imports to pay for the border wall. This by itself is not surprising, as it is the only option that could be realistically claimed as making Mexico pay up.

The thing is, it doesn’t make any economic sense.

As anyone with common sense can predict, sellers of Mexican products will certainly shift a significant portion of the tariff to American consumers. Any decent ECON 101 would have taught the logic behind tax burden, and unless Mexico have no alternative use of their productivity, Americans consumers will have to pay a lot.

Some might say buying American would solve the problem. Or does it? Suppose every Americans decide to become true patriots and stop buying Mexican products—most likely out of patriotism to their wallets—such that import from Mexico drops to zero. Guess what? The tariff revenue will be zero. So ironically, the more patriotic Americans are, the more they will be paying for the wall.

This type of nonsense is what makes Trump so dangerous. He doesn’t care about the practicality of his orders and the whole country has no choice but to go along with him.