Essential Mathematics for Economics

CapitalOne Quicksilver 0% intro APR (2)

less than 1 minute read

Published: August 06, 2025

In my post, I mentioned I opened the CapitalOne Quicksilver Card because it offered 0% intro APR for 15 months (and the card has no annual fee and gives 1.5% cash back on all purchases).

I have been using the card for about half a year, and so far I am very happy. In particular, I paid my federal and state income taxes using the card, so I essentially deferred the tax payment by one year, interest-free. (The IRS charges 1.75% fee for paying taxes with a credit card, but because the card gives 1.5% cash back, it is nearly offset.) I highly recommend the card to anybody. If you open an account by clicking this link, you will receive an extra sign up bonus.

On illegal immigrants

1 minute read

Published: June 21, 2025

If a person enters my house without my permission, I suppose I have the right to ask the person to leave, and if they refuse, I may force them to do so. By analogy, if a person crosses the border into a country without permission from the government of that country, I suppose the government has the right to ask the person to leave, and if they refuse, they may force them to do so. Therefore, I see no problem that some government cracks down illegal immigration and attempts to deport illegal immigrants (although there may be exceptions on an individual basis, for example children that were taken to the country by their illegal immigrant parents and grew up for quite some time, losing tie to their country of birth). It is just common sense that follows from the fundamental principle of a liberal society that honors property rights. A corollary of this argument is that I do not understand why some people (typically the radical left or whatever they are called) organize protests against the crack down of illegal immigration.

夏目漱石全集

less than 1 minute read

Published: June 20, 2025

だいぶ前の話になるけど、アトランタへの通勤の時間を有効に使おうと思って、Amazon Kindleで夏目漱石全集を2ドルだか3ドルで買った。主要作品は文庫本で持っているけど、マイナーな作品も読めてとてもよかった。

Is WTN necessary?

3 minute read

Published: March 25, 2025

Among amateur tennis players, including high school and college players, I think it is fair to say that UTR (Universal Tennis Rating) is the number that we look at to measure the skill level. UTR rates tennis players by a number between 1 and 16 something, with a higher number indicating higher skill level. According to the Wikipedia page, UTR was developed by a private company in 2008 to evaluate junior players.