Price Transmission in the Value Chain of Hard Clam in Vietnam

Using data collected from 2007-2010, this study identifies price linkages and then forecasts vertical price transmission elasticities between markets (farm, wholesale, retail and export) in the value chain of hard clam (Meratrix lyrata) in Vietnam. After doing necessary tests to make sure that all price data are stationary, Seemingly Unrelated Regression (SUR) and Error Correction Model (ECM) are employed to examine short-time and long-time effects of hard clam price in one market on the other market in its value chain. The seemingly unrelated regression results show that hard clam prices seem not depend on seasons. Farm price of hard clam is transmitted completely to wholesale price while the price in retail market causes negative effect on farm price in the short run. Wholesale price of hard clam is transmitted to both prices in farm and retail markets. The export price of hard clam is estimated not to be affected in the short run by prices in other markets except retail price in domestic markets. Error correction models confirm the independence of hard clam price on annual seasons. The transmission elasticities of prices between the markets are also identified based on model estimation.