The government has asked consumer product manufacturers to inform officials 15-30 days in advance before changing the sizes and prices of their products.
It has also asked modern traders to reaffirm the prices of products with the Internal Trade Department before selling them.
Deputy Commerce Minister Sontirat Sontijirawong said the request seems to be the appropriate solution for allegations from consumers of indirect price increases.
The Commerce Ministry yesterday held a joint meeting with Saha Group, Unilever Thai Trading Ltd, Colgate-Palmolive Thailand, Procter & Gamble Trading Thailand, Big C Supercenter, Home Product Center Plc (the operator of HomePro stores) and Ek-chai Distribution System (the operator of Tesco Lotus hypermarkets) after consumers complained about being charged the same price for products that are smaller in size or volume.
The meeting found that two items -- certain brands of shower gel and liquid detergents -- have seen size and volume cuts while being sold at the same price, with the manufacturers saying their chemical production costs have risen over the past two to three years amid stiffer competition.
Mr Sontirat said such practices are not yet treated as illegal, as the product prices remain lower than the reference prices previously communicated to the ministry.
More importantly, those products are on the Commerce Ministry's watch list, not the price control list. The price control list covers essential items for daily use such as food, consumer goods, farm-related products, paper, petroleum and medicine.
The government earlier this year raised the number of products and services on the state price control list to 47, up from 45. Delivery charges for online shopping and counter services were added to the list of expenditures that need special supervision due to growing usage.
The three service items that were already on the list are commercial usage of copyrighted music, storage and warehousing services and agricultural services.
The number of products on the price control list will stay unchanged at 42.
Consumer products include detergents, sanitary napkins and toilet paper.