One Sunday last month, Zhu Jing took his son to the zoo in Hangzhou, the capital of east China's Zhejiang Province, and was asked to buy two tickets: one for himself and the other for his five-year-old boy.

Zhu was upset.

He argued that according to the zoo's regulations, his son, a preschool child, should be admitted free of charge.

But zoo staff told him the boy's height was above 1.1 meters and the regulation also says only those under that height need not pay.

Back in 1949, the central government ordered that places of entertainment and transportation agencies should not charge kids under seven years old and less than 1.1 meters tall.

The regulation is still in use in most parts of the country.

It is quite common to see a red line at bus doors or the entry to entertainment spots marking the 1.1-meter height. Those who are taller have to buy tickets.

In the early days of the PRC, many children seven years old or younger were below 1.1 meter in height.

However, the average height of a five-year-old Chinese kid now is 1.2 meters, 10 centimeters or so taller than children half a century ago, says an expert on children's studies.

Chinese children have grown by an extra 2.3 to 3 centimeters every decade in the past 50 years, according to Li Hui, a senior physician at the Beijing Municipal Children's Studies Institute.

Wang Ying, deputy director of a kindergarten in Shenyang, capital of northeast China's Liaoning Province, tells China Daily that more than one-third of children around six years old are 1.2 meters tall.

She explains that improved living standards, good nutrition and athletic activities have helped to stimulate their growth.

As a result, many children have lost the privilege of free rides or entry; and social activists and parents are pressing for a change in the outdated regulation.

Fang Tingyu, a medical expert, told Xinhua News Agency that the criterion should hinge on children's age instead of height.

But the age criterion also has some difficulties, says another expert.

Chinese children do not have documents proving their age until they are 16 years old, when they are entitled to apply for an ID card on which their birth date is clearly recorded.

Zhou Xiaozheng, a well-known commentator and sociology professor at Beijing's Renmin University, suggests a public hearing, like those for commodity prices, be held to discuss the issue. Others simply say a new standard needs to be set.

However, the regulation in most parts of the country still remains unchanged and only a few provinces and cities have taken action to update the standard.

"As a matter of fact, it's an issue affecting many people's interests," says Zhang Yong, deputy director of the Bureau of Commodity Price of Liaoning Province.

In October 2002, Liaoning Province altered its height line to 1.3 meters.

He recalls that immediately after the new standard was set, they were under pressure from various interest groups such as the long-distance passenger transport department.

They argued that raising the height line directly reduced their revenues because the kids enjoying a free ride still occupy a seat just like an adult. The change effectively decreased every coach's capacity for paying passengers.

(China Daily March 19, 2004)