To the nines

"In China, interest rates are always set to be multiples of nine," said Fan Wenzhong, deputy director at the Research Department of the China Banking Regulatory Commission in Beijing.

Because the financial year in China has 360 days, it's easier to compute monthly and daily rates if yearly rates are evenly divisible by nine, as are the current lending and deposit rates. The divisible-by-nine rule was enshrined in accounting standards issued jointly by the central bank and the Ministry of Finance in 1993.

The rule also simplifies interest computation on an abacus, the calculating tool that came into use more than 2,000 years ago during the Han Dynasty and is still used today.

"Rates divisible by nine avoid rounding of interest and allow easier calculation by abacus," said Wang Qing, chief China economist at Morgan Stanley in Hong Kong.

In addition, the number nine in Chinese shares a pronunciation with the word "longevity" and has long been considered a lucky number. Chinese wedding feasts have nine dishes; Beijing's Forbidden City has 9,999 rooms.

"The number nine is very important in the Chinese society and business world," said Chan Mansing, associate professor at the School of Chinese at the University of Hong Kong. "Nine stands for longevity, abundance and masculinity. It also represents the highest attainable level in all human endeavors in the Book of Change, a Chinese philosophy book that has been read for thousands of years."

I'm skeptical about some of that, particularly the number of rooms in the Forbidden City.