This group of economies is of interest for a number of reasons. Firstly, they feature great diversity – Singapore has one of the highest per capita incomes in the world, while several of the mainland Southeast Asian states are among the poorest. Brunei is a tiny oil sultanate, while Indonesia is the world’s fourth largest nation. In addition, several of these economies have been consistently among the world’s most open, while others are emerging from a long period of international commercial isolation. Thirdly, the group includes one sizeable country, the Philippines, which for reasons still only poorly understood has consistently under-performed compared to its potential. Four of the economies – Indonesia, Malaysia, Singapore, Thailand – grew extremely quickly in the three decades through to the recent Asian economic crisis.