【明報專訊】THE PEOPLE'S BANK OF CHINA (PBC) has devalued the yuan by about 2% ostensibly to improve the exchange rate mechanism. The drop is the largest one-day fall since 2005, when the exchange rate reform was effected. The move has impacted on the world, especially on Asia-Pacific financial markets. On the face of it, it will go some way towards boosting the mainland's exports, increasing its competitiveness and fostering its economic growth. Furthermore, some analysts have suggested that a clever combination of devaluation and exchange-rate marketisation will make it likelier for the International Monetary Fund (IMF) to include the yuan in what is called Special Drawing Rights (SDR). Nevertheless, the central bank has devalued the yuan mainly to tackle economic stagnation on the mainland. It remains to be seen whether the move will help improve its exports. As for Hong Kong, the move is expected to hit its tourist industry and thus its economy as a whole since it is highly reliant on the mainland economically and its exchange rate policy cannot possibly be brought into line with the mainland's.