CHATRUDEE THEPARAT & PHUSADEE ARUNMAS

Amid growing concern that the country's inflation rate is higher than the official statistics indicate, government economists insist their methods and calculations are an accurate reflection of price increases.

Analysts expect May inflation figures, due for release today, to be sharply higher than the 6.2% figure posted for April, which was a two-year high.

But for consumers who are seeing double-digit rises in prices of food and fuel, the figures don't seem to add up.

Nateetip Tongkoaon, director of the Trade Economic Indices Bureau of the Commerce Ministry, maintains that the inflation rate is not unrealistically low, noting that rates vary widely across the region depending on local factors.

In April, for instance, while food and fuel costs pushed Thailand's Consumer Price Index up 6.2% from a year earlier, comparable figures were 3% in Malaysia, 9% in Indonesia, 6% in Singapore and 21% in Vietnam.

The annual inflation rate in 2007 averaged 2.3% but Mrs Nateetip pointed out that the former military-installed government had strictly controlled prices, so producers last year were unable to raise prices to match increasing costs.

This year, producers have been gradually asking for price increase in keeping with higher raw material costs.

The local inflation rate is calculated based on the prices of 373 products and services nationwide, using 2002 as the base year, Mrs Nateetip explained.

The basket covers almost all sectors, including food and beverages, apparel, housing and furnishings, medical and personal care, transport and communication, entertainment, recreation and education. Information is collected based on surveys of real market prices.

For instance, information on food is gathered from both traditional fresh markets as well as modern supermarkets and hypermarts, where an increasing number of urban consumers shop.

One significant factor keeping a lid on inflation is that Thailand has abundant food supplies.

According to Mrs Nateetip, the base year for calculations will soon change to reflect updated conditions. The National Statistical Office next month will release a survey of household spending for 2007 as the base year.

Changes could also be made in the product basket if the National Statistical Office deems them necessary, she said.

Mrs Nateetip noted that gasohol and biodiesel were now in the basket to more accurately reflect fuel consumption. However, subway and skytrain fares have yet to be included.

''We insist the government does not [keep the inflation figure low]. The rate you see is a result of many measures implemented recently, such as requests for operators to freeze their prices or delay price increases of their products,'' she said. ''In addition, the ministry's Blue Flag low-cost product scheme also helps alleviate the higher cost of living.''

Ampon Kittiampon, the secretary-general of the National Economic and Social Development Board (NESDB), said the methods used in Thailand to measure inflation were quite close to those of other countries.

He said the inflation rate might seem low but there are some mitigating factors. For example, natural gas accounts for 70% of the fuel used to produce electricity in Thailand. If power producers had to rely more on oil, electricity would cost more and that would affect businesses and consumers across the board.

The previous government's decision to scrap fuel subsidies, meanwhile, has prompted the public to save energy and reduce oil consumption. The inflation rate today might be much higher if the government was still subsidising fuel prices for general motorists.

Mr Ampon said inflationary pressure would be eased if the government encouraged a shift in goods transport from road to rail, especially for key routes linking Bangkok to Nakhon Sawan, Nakhon Ratchasima, Khon Kaen, and to Laem Chabang.