Singapore takes in new immigrants to keep population numbers steady, but must manage the inflow carefully, said Prime Minister Lee Hsien Loong yesterday.
The people who come must be able to integrate into society, have the abilities and skills to contribute to the economy and have their hearts in the right place, he added at a citizenship ceremony at Townsville Primary School.
About 20,000 people become new citizens here every year.
Together with the 30,000 Singaporean babies born, this adds 50,000 to Singapore's citizen population each year.
This allows Singapore to have a stable population, as Singaporeans are far from replacing themselves with a total fertility rate (TFR) of 1.3, said Mr Lee.
The TFR measures the average number of children per woman, and needs to be at least 2.1 for the population to replace itself.
Mr Lee said ideally, more Singaporean babies should be born, so the Government has worked to support young families through marriage and parenthood policies.
Over the years, schemes have been launched in the areas of housing, pre-school services, workplace and community support to encourage people to start families.
Singapore University of Social Sciences sociologist Kang Soon-Hock said enough time must be given for policy enhancements to take effect.
In the meantime, maintaining a stable population is needed to stave off labour shortages as the population ages and there are fewer working-age people.
National University of Singapore sociologist Paulin Straughan said there is a limit to how much the TFR can be pushed up, so other strategies are needed to sustain population growth.
For instance, making Singapore an attractive destination for talented residents, so the country can "pick and attract people who can bring the best to Singapore".
Mr Lee, an MP for Ang Mo Kio GRC, presented 150 new citizens with their citizenship certificates and identity cards at the ceremony for Ang Mo Kio GRC and Sengkang West SMC residents yesterday.
"When you take up Singapore citizenship, you are not just becoming a resident of this island or a worker. You are committing your loyalty to Singapore, pledging yourself to fulfil the responsibilities of a citizen," he said as he congratulated them.
"You have chosen to take up Singapore citizenship because you believe in Singapore and identify yourself with what Singapore stands for - a harmonious multiracial, multi-religious country, a fair and just society where people have opportunities to succeed if they work hard, (and) a cohesive community where Singaporeans care for one another and help one another succeed."
He added that he hoped they will continue to contribute to society, as some new citizens, such as Madam Angie Ng, 41, have done.
She left her position as a quality manager in Melaka to move to Singapore when her husband accepted a job offer here in 2011, and has been actively involved in the community.
Besides looking after her two sons, the housewife volunteersat Teck Ghee Community Club, organising events and explaining policies such as MediShield Life and the Silver Support Scheme to seniors.
"Being a volunteer helped me to integrate better and get to know others better," she said.
"Now that we're citizens here, we should contribute to the place where we reside."