"Asean markets have done particularly well as foreign investors, especially large institutions, tend to target north Asia, " said Khiem Do, head of Asian Multi-Asset Strategy at Barings Asset Management, referring to the Association of Southeast Asian Nations, a regional grouping.

WSJ: Asia as Investor Haven? Market Rout Says Not

Grouping together in the same place is supposed to help small firms remain competitive, as management gurus such as Michael Porter have argued, since they can tap the deep local pools of skilled workers, finance and suppliers.

ECONOMIST: Italy's business clusters