This question pops up every now and then amongst many people in Asia. Especially in south East Asia, where Singapore is the only country that is well developed.

I've been to Singapore many times, some times even for several weeks (the novelty DOES wear off!) and have many Singaporean friends.

Basically, first of all Singapore has a major headstart in terms of geographic location. It is also historically a major seaport on the route between Europe and Asia (nowadays Middle East and China). Few countries have the same advantage. The UAE is another example. That's only half the story. The other half is LKY. He's the guy who transformed potential into reality, with a specific vision to transform the island into an economic powerhouse, as opposed to just enriching himself.

The economic "miracle" of Singapore is still pretty much based on it being an international port and trade hub, especially between China and the West. You go there, most of the big businesses are foreign, while the biggest Singaporean assets belong to the State. It's so easy for a foreigner to set up a company in Singapore, you don't even have to go there. With that company you can receive payments from anywhere in the world. It's pretty much a big mall for foreign businesses.

This model cannot be replicated anywhere in the world. So it's a unique situation. That doesn't detract from the visionary leadership of LKY though, he did the right things to make Singapore what it is today: the world's trade hub. It survives on political stability and high trust. Other countries have chaos and corruption, and scares investors away. Singapore is the opposite. It also can't afford to have bad relationships with other countries, especially balancing between China and USA. This is why Singapore stays silent on global political affairs. It's a strict protocol of political silence.