An anti-dumping measure is a trade regulation many countries use to prevent local industries from being hurt by cheap imported goods that are "dumped" on the market.
Thailand is a member of the World Trade Organization, which has adopted international free trade regulations including an anti-dumping mechanism. This mechanism is meant to be applied in conjunction with a local law.
Thailand's law is the Anti-Dumping Act (1999). Here are some brief details about how the regulation works.
Definition: Dumping is when the export price of a good is lower than the domestic price. This could signal there are export subsidies or a trade procedure that enables the export price to be lower.
Local producers must file complaints against the foreign companies dumping the goods if they find the export price is below the domestic price in their homeland. The complaint is filed with the Commerce Ministry, which oversees the anti-dumping regulation.
If the Commerce Ministry finds a price gap between the two countries, it will start an investigation to determine dumping.
The investigation could take several months as more documents, facts and data are requested from the local industry hurt by the imported goods as well as from neutral agencies. The ministry will interview all relevant parties to determine the harm incurred by dumped goods.
During the investigation period, the foreign companies accused can defend themselves. Typically the government of the foreign companies will appoint relevant authorities to act as a defendant in the probe.
If the investigation determines dumping occurred and injured local industries, the Commerce Ministry will impose an anti-dumping tariff on the imports. The anti-dumping tariff is normally equivalent to the price gap, helping both players to compete fairly.