For the past 40 years, consumers have had the upper-hand in the global rice market, which has witnessed a steady decline in prices, interrupted only by the brief spike in 1973-74 triggered by the first oil crisis. The structural decline in prices was the result of the Green Revolution, the agronomics movement that spread the use of irrigation, fertiliser and high-yielding varieties of rice in Asia in the late 1960s and led to bumper crops. Rice production per hectare jumped in developing countries from 1.7 tonnes in 1961 to 4 tonnes in 2006. This "buyers' market', however, has flipped abruptly this year into a "sellers' market' because of a fundamental change in the balance between supply and demand. This is likely to keep prices in the medium-term well above historical levels, analysts and traders say. The price of Thai medium-quality rice, a global benchmark, traded on Wednesday at a record high of $854 a tonne, according to Thailand's rice export association. It has more than doubled since the end of last year. The World Bank on Wednesday said that average rice prices would rise further in 2009 and 2010, although the increase would be much less steeper than the current jump. Vichai Sriprasert, president of Riceland International, a leading Thai exporter in Bangkok, says that sellers determine the market. "It is very clear that farmers, millers and traders have the upper hand now,' Mr Sriprasert says. A combination of factors have led to prices rising. Consumption in Asia, the Middle East and West Africa is booming, thanks to rising per capita income (which allows more people to enjoy three meals a day instead of just one or two); poor supplies due to a reduction in acreage devoted to the crop; rising costs of fuel and fertilisers; and the exhaustion of technological advances that contributed to a surge in rice yields in the past. From aromatic to long-grain Rice is not a homogenous commodity, unlike maize, wheat and soyabeans. There are more than 50 different prices for rice quoted internationally at present, with prices ranging from more than $1,500 a tonne for the high-end basmati rice to less than $600 a tonne for the lower-quality varieties. The international rice market can be broken down into several sub-markets, depending on the variety, quality and degree of processing. Broadly speaking, the indica variety, characterised by its long grain, is the most abundant, making up about 75 per cent of the market. It is followed by the japonica medium-grain, with 12 per cent of the market. Aromatic rice, such as the prized Thai jasmine and the Indian basmati, makes up the rest of the market. The fragmented nature of the market has thwarted the establishment of internationally recognised grades and delayed the establishment of futures markets, says the UN's Food and Agriculture Organisation. The only significant futures market, located in Chicago, provides pricing reference for a fraction of the rice produced in the US, and has no relevance for Asia prices, traders say. Water shortages in southeast Asia, Central America and West Africa have also contributed to a slowdown in production growth, while higher labour cost in countries such as Vietnam as more people move to cities have increased production cost significantly, experts say. Demand has outstripped production in six of the past eight years and global rice stocks have fallen to their lowest level since 1976. Concepci