SINGAPORE's economic model combining a good social safety net with low tax rates is not easily copied as each country has a different starting point, said Minister Mentor Lee Kuan Yew on Wednesday.

But one advice he can give is: You cannot take back what is given.

'You start off with the premise that once given, if you take it back, there's a tremendous penalty in the votes that you'll get. So once given, it cannot be taken back,' he said at the Forbes CEO global conference.

This was Singapore's position from the day it became independent, he said, after having watched the British implement some of their policies here in the 1950s which he described as 'the way to ruin'.

So when the People's Action Party took charge, it stopped 'free prescriptions for medicine...started putting charges on them which we kept on making more and more realistic'.

But this is Singapore's way, which other countries may not be able to follow.

'You can't copy another country's policy, because you've already got a different starting point,' he noted.

Mr Lee was responding to a question by publishing tycoon Steve Forbes on how other countries could learn from Singapore, which has managed to build a good social safety net despite low taxes.

Singaporeans pay among the lowest personal income taxes in the world, with the top rate capped at 20 per cent. It also has schemes like Workfare Income Supplement to boost the earnings of low-wage workers.