Thailand's export sector and foreign direct investment will take a hit because Malaysia and Vietnam, for example, are both TPP and RCEP members. For exports, TPP is expected to enforce a new set of rules on origin of goods, which will effectively hurt exporters who are not members, as they may not be able to ship products to TPP markets such as the US.
This in turn will hurt foreign direct investment in Thailand, as new manufacturing projects will be diverted to Malaysia or Vietnam.
Previously, Thailand did not take a clear position on joining the TPP whose 12 founding member countries recently reached an agreement in the US, partly because of some issues such as domestic political chaos and fears of expensive drugs from becoming a TPP member.
The government should now review its TPP position to ensure that the country does not miss potential economic opportunities resulting from this powerful grouping.