And the happiest places? Those in northern Europe topped the list, with Denmark narrowly edging out Norway and Switzerland to claim the crown of contentment. The United States ranked 17th.

Lingnan University Professor Ho Lok-sang, who has run a happiness survey since 2005, said Hong Kong's ranking was in line with his findings.

"Hong Kong's level of happiness is respectable. It is not bad at all," he said. "However, I am slightly surprised as I thought it would be ahead of Singapore."

Singaporeans' extra disposable income, as well as their superior housing situation, could account for the disparity, Ho said.

Published by the UN Sustainable Development Solutions Network, the report drew on Gallup World Poll data from the past three years to rank countries by factors including life expectancy, perceptions of corruption, gross domestic product per capita and social support.

Countries were rated on a 0-10 scale, with scores ranging from 2.936 (Togo) to 7.639 (Denmark). Hong Kong scored 5.523.

But Ho was not convinced by the methodology, saying it measured satisfaction - not happiness - and respondents were more likely to respond negatively to questions about satisfaction.

"If we ask about satisfaction, people look for a reason to complain," Ho said, adding that this was not the case with happiness.

Several locals were hesitant to say it was a happy place, citing the fast-paced, stressful environment. "I think it's because of the lack of space and the increasing population," said Amy Chung, a lawyer. "It's hard to find a place to relax. Have you seen grass here?"

Terry Choi, who works in finance, said: "The working hours are long and life is stressful.

"But Hong Kong is secure - especially compared with [mainland] China."