HONG KONG, Jan. 18 (Xinhua) -- It was a big mistake for the International Monetary Fund (IMF) not to include the Chinese currency, renminbi (RMB), in the international reserve basket in its recent reevaluation of the content of SDRs, said Nobel Prize- winning economist Robert Mundell on Tuesday at the 4th Asian Financial Forum in Hong Kong.

IMF should take the opportunity to put RMB in the basket for China is now the biggest exporter in the world and the No. 2 economy, said Mundell, describing IMF as missing the forest for the trees.

Mundell said arguments that RMB is not convertible were only good technically because IMF once did put unconvertible currency in the basket when it was made in 1974.

RMB was the only inconvertible currency that I knew of in history that was expected to appreciate, he added.

Speaking of RMB, Mundell also noted that very substantial appreciation of the currency was a no-no for China, which will be devastating and the worst possible thing to the country.

It certainly will do no great harm at the rate of 2 percent to 3 percent, which may do some good on tempering inflation pressures in the country, he said.

In his speech, Mundell also suggested that China should raise the proportion of consumption in its economy from the current level, which is shockingly low compared to other countries, to 45 percent to 50 percent so as to realize a more balanced trade.