Thailand is richer than Portugal, but why...?

[Alex]

Thailand has a higher GDP than Portugal. Thailand has around 600 billion, while Portugal is 200 billion. Why is Thailand considered a third world country while Portugal is first world? Why do the Thais need visas to visit other countries while Portuguese doesn't?

[Helena Megre]

Because Thailand is not richer than Portugal.
Thailand has a bigger economy, because it has a bigger population (65 million thai against 10 million portuguese). In other words, more people consume more goods and produce a bigger market, yet, each portuguese produces more money than a Thai.
GDP per Capita (the amount of money produced by each person), is the measure used to see if an economy is "developed" or not, and Thailand's GDP per Capita is 2,5 times smaller than in Portugal.
Also, socially (HDI), Portugal is ranked among the most developed countries in the world, while Thailand is not, and that grants security that the probability of a mass emigration from Portugal is out of the equation, thus other developed countries grant Portugal a no visa policy.

In other words, it's not the size of a national market that shows how developed a country is (if that was the case, China would be 1st World and Switzerland 3rd world).
Proportional wealth and social development is what is used to see how developed a country is.