Like Hong Kong's economy, the cost of daily caffeine fixes in coffee shops is on the boil. No matter what your preference - latte, cappuccino, espresso - the cost, in general, has gone up between $1 and $2 a cup in all the city's recognised coffee houses. The cost of a cup of coffee at Starbucks has risen by $2 since April 9, while in Pacific Coffee shops the price has increased $1 since last month. Rob Naylor, chief operating officer of Pacific Coffee, said rising rents, labour costs and price increases for commodities such as milk had been contributing factors. The London-based International Coffee Organisation said the increases had been driven by a worldwide shortage of coffee beans due to drought, and the stockpiling of beans in some producer countries in the expectation that frosty weather would reduce harvests and force prices even higher. Mr Naylor said the price of the high-quality coffee beans his company uses had soared by up to 40 per cent this year because of supply shortages. Coffee prices this month seemed to confirm the upward trend that began last September. The monthly average price of one pound (1/2kg) of Colombian mild arabica reached US$1.30 in April against last year's 77 US cents on the New York futures markets, about 69 per cent higher year on year. 'As coffee is the second-largest commodity traded in the world - after crude oil - the rumour is that it is attracting hedge-fund investment which will further push up prices,' Mr Naylor said. Tsit Wing, one of Hong Kong's largest importers of green beans, said prices had risen more than 50 per cent since last October. Hong Kong imported $107.2 million worth of coffee last year.