Property curbs in Singapore for foreign buyers

Despite numerous curbs initiated by the Singapore govt, property prices in Singapore are in no way coming down, especially the new properties. Came across an article last Thursday on the Straits Times about property curbs across Asia which was kind of interesting. There was a map showing property curbs in multiple countries, Singapore being one of them.

It is a no brainer looking at this map why prices aren't falling despite curbs on loans, increases in stamp duties etc. If I were a foreigner looking for some place to park my money, a 15% stamp duty isnt going to deter me. If the govt was serious about cooling the market, they should bump up stamp duties for foreigners and PRs to a larger number like 35%. PRs should be forced to sell properties once they do not reside in the country any more. I do not have the data on this but, before you know it, half of Singapore will be owned by foreigners and foreign countries (if it hasn't happened already...).