A prosperous region and a people whose skills rise across the board are two key factors that will keep Singapore's economy moving forward in the next 10 to 20 years, Prime Minister Lee Hsien Loong said yesterday.

"We must assume and hope that our neighbours will be making progress towards First World standards," he said at a dialogue during the annual Singapore Summit at Marina Bay Sands. "If they don't, then we are always in a neighbourhood where there are opportunities, but it will be a drag on us."

While Singapore has switched gears now that it is no longer a nascent economy with untapped manpower capacity, it has to stay open and dynamic - not just in terms of borders, but also in terms of mindsets, Mr Lee said.

"When you are no longer a teenager, you are no longer as bouncy as before. But if you stop growing, either in terms of your perspective or in terms of your capabilities, then you decline," he said.

"We have to adapt, we have to evolve, we have to absorb ideas, experiences, talent from many parts of the world but at the same time, there is some essence and spirit of Singapore which is valuable and you don't want to wake up tomorrow and find that that's gone. As long as our own population is stable, I think we can manage that."

Mr Lee noted that Singapore had done an economic review every five to 10 years since 1985, and said perhaps it was time to take a look again. The last report, by the Economic Strategies Committee, was published in February 2010.

He noted that incomes have risen across the board, including at the lower end. And although the income gap has widened in the last 15 years, there have been improvements in the past two to four years.

This is not the case in most other countries where incomes at the lower end have stagnated, he said.

"Whether we can keep it stable depends on how well we are able to upgrade the lower end of the income earners," he said. "To have that kind of society where you can move up in life from the bottom to the top and people don't hold it against you that you don't quite know how to dress the right way or don't have quite the right accent."

One challenge was the new wave of technology, be it robotics or artificial intelligence. While industrialisation in the past meant greater automation of physical labour, newer technologies are seeking to automate intellectual labour.

This means that human beings must be able to keep training themselves in more complex skills. But this is a happy, if not trivial, problem to have compared to being frozen for the next 50 years, he said.

Asked for three words to describe the Singapore he wanted to see in 50 years, he said: resilience, survivability and a uniqueness that Singaporeans are proud of.

The first two will help the country deal with and overcome difficulties such as climate change and global terrorism, while the final quality provides the impetus for Singaporeans to stick around and build a brighter future here.

"If you are not special, and there could be any number of other cities in the world where Singaporeans will be completely comfortable, then what is it that holds them in Singapore and makes them want to keep Singapore going?"

"It has to be something different, and we have to be proud of that. Then we can make it work, and our children, we hope, will feel that yes, I have grown up in a place which I truly appreciate and one day I will help make it work too."

Asked if the Government still had to be paranoid about Singapore's "survivability" after 50 years, he said: "Only the paranoid survive."

"We don't think that we will vanish from the face of the earth tomorrow," he said. "On the other hand, we remember the frogs which don't notice temperatures going up and gradually get boiled swimming around in warm water."