But the dynamism of Hong Kong that rubbed off on him for four years kept 'bugging' him.

So, when the opportunity arose, Professor Chang decided to come back to become head of the City University, where he had served as a council member when he was teaching at UST.

What propelled him to leave North America, where he had lived for 29 years and where 90 per cent of his family still lives, is that same yearning to be able to make a difference.

Professor Chang believes a similar yearning - not Hong Kong's arguably attractive remuneration package - also motivates a growing number of world-class academics to teach at Hong Kong's tertiary institutions.

'Some people want to do something that is meaningful. Even though they may be top-rate professors and good researchers, they have a basic yearning to do something significant and want to know that they can make a difference,' he said.

'It's difficult to feel that at Berkeley, or Stanford or Harvard. It's possible to do so in Hong Kong, because Hong Kong is expanding and Hong Kong's academic ranks are improving.

'We're at a point where we do not have a lot of indigenous scholars who can match their [the top academics'] quality. But we're at a point where we're ready and able to benefit from them and offer the right kind of support, intellectual stimulation and input to them.

'I think at least half the people who are really stellar quality and first-rate are movable. But you have to present enough of a vision, enough of a future, combined with a comfortable remuneration package.' While Hong Kong universities' remuneration packages are not bad compared to those of Australian, British and some American institutions, Professor Chang said it was unfair to say the territory was using first-class pay to recruit second-rate academics from overseas.

'What people fail to understand is that in the United States, the consultancy rules are much less rigid,' he said, so that academics could pocket consultancy fees instead of giving them to the universities.

Professor Chang also notes that the housing benefits which expatriates get are not necessarily as generous as people think.

'We give them only a 130-square-metre apartment. That's considered very good by Hong Kong's standards. But you've got to put in their wives' point of view. They had a yard, a swimming pool, a lot of land. Yes, they didn't cost much. But [coming to Hong Kong] is to trade that much space for this space. We think we're giving them extra benefit. It is extra benefit. But they're certainly not coming here for the 130-sq m apartment.

'Overall, they come here because they feel they can make a difference. They have friends who have succeeded, been happy, because Hong Kong is a place you can grow used to.' So what difference is Professor Chang going to make at the City University? Spelling out his vision in his inaugural address, he talked of leading the university with more than 17,000 full-time and part-time students and 800 staff through 'three Ts and three As'.

The three Ts are transition to a society of knowledge, transition of Hong Kong from a British colony to a special administrative region of China, and transformation of the City University from a former polytechnic to a fully-fledged university, while the three As stand for academic excellence, ambience for intellectual growth and accountability.

As a first step towards achieving his goals, Professor Chang will set up and chair three task forces.

The first aims to improve the campus environment so that students will feel they are in a cultured and learned atmosphere.

The second will map out plans to convert the university's course structure into a credit unit system and to introduce elective subjects to broaden students' academic development.

The third seeks to enhance the language proficiency of students and the wider use of English on the campus.

Some may wonder at the wisdom of promoting English when Putonghua is becoming more important as the territory is about to return to Chinese rule and there is pressure for secondary schools to use Cantonese instead of English.

But to Professor Chang, whose mother tongue is Putonghua, the move to promote English is necessary for societal reasons.

'For whatever reasons, over the last 200 years English has been the dominant international language. It will remain so at least for the next 100 years. Science, technology, commerce, diplomacy, tourism. Everything is done in English. A Czech and a Pole can communicate only in English,' he said.

'Hong Kong's advantage, whether it is part of China or not, lies in its international contact. It lies in its facilities to function in English. If our university graduates are no longer fully conversant in English, then that advantage will be lost.' Professor Chang said he was aware of complaints by employers of the quality of graduates and their falling language proficiency, but felt the matter must be seen in a wider perspective.

He recalled that when he visited Hong Kong in 1989, only about eight per cent of young people in the relevant age group were in tertiary institutions.

But then the Government decided to more than double provision before 1997, after the crackdown on the student movement in the summer of 1989 in Beijing prompted big waves of emigration and fuelled concern about a skills shortage.

Whereas a similar tertiary expansion in the United States took more than 30 years, the whole increase in Hong Kong was compressed into five or six years.

The problem was tertiary institutions did not know quite what to do with both expanding quantitatively and keeping the quality together, while secondary schools also had difficulty educating a larger percentage of their students for tertiary education.

'[However] because of the compression, people's memories of the differences in quality were very vivid. It's very easy for employers to compare a Hong Kong university graduate six years ago with one from today.' What the community must realise, said Professor Chang, was that when tertiary education provision expanded from a few per cent to nearly 20 per cent, the total population could not be as smart as the first few per cent.

Despite complaints about the quality of students, Professor Chang said the ones he had encountered were certainly no worse than those he had taught in North America. 'And I had only taught at first-rate universities in North America,' he said.

Professor Chang first visited Hong Kong in 1963. He had just graduated from the National Taiwan University and was on his way to Ethiopia to see his parents before going to the United States to pursue graduate studies.

His father was a professor of surgery and his mother a gynaecologist; they were working for the World Health Organisation, starting up a medical school in the African country.

Thirty-three years on, Professor Chang still has a vivid memory of his two-day stay in the territory. A friend drove him up to the top of Kowloon Peak from where he had a panoramic view of east Kowloon.

'It was nothing much at all. Kai Tak airport looked like a suburb in the wilderness,' he recalled.

But the breathtaking view has since stuck in his mind. So has the sight of the sizzling steak he devoured at the restaurant of the Ambassador Hotel in Tsim Sha Tsui and the four-hour-a-day water rationing rule he endured at his friend's home.

Looking back, 'it must have sown the seed' of his decision to complete his career here, he said.

Interestingly, the view of another beautiful spot also played a role in prompting him to accept his first appointment in Hong Kong.

Professor Chang recalled that UST vice-chancellor, Professor Woo Chia-wei, prodded him for over a year to visit. When he arrived, he was promptly taken to the scenic site near Clearwater Bay where the UST was to be built.

'It was so beautiful, and I thought if I could help build something using my best knowledge, if I could really shape the future of this university, it was probably better than doing research in a laboratory cutting up animals and so forth. So I decided, maybe there and then, that I would consider coming.'