Arvind Subramanian’s piece in the FT arguing that the renminbi could become the world’s reserve currency within a decade strikes a chord since I spent the past couple of weeks in Hong Kong and China.

Rather like Mandarin is already rivalling Cantonese as a language in Guangdong province, Hong Kong residents are increasingly keen to hold savings in renminbi over Hong Kong dollars, given the latter’s peg to the US dollar.

I found myself looking at my spare renminbi notes with new respect at the end of my trip. On current trends, holding cash in the Chinese currency is one of the safest bets there is – it is heavily undervalued internationally and the government is allowing a slow, steady rise against the dollar.

The renminbi is not a convertible currency, so those outside China cannot simply open a renminbi savings account – if they could, it would soon face similar problems to the Swiss franc. A more or less guaranteed 5 per cent capital appreciation plus interest would be a nice investment for those long the dollar.

Still, China is doing its best to encourage an offshore renminbi market both in Hong Kong and in London, even if it is getting off to a slow start. The market is already making its views known.