Price transmission in the pangasius value chain from Vietnam to Germany

•Market integration is found by both bivariate and trivariate testing.•The Law of One Price is rejected, indicating imperfect price transmission.•Weak exogeneity tests fail to reject downstream market leadership of the value chain.•Pangasius farmers can expand without fearing that self-inflicted price reductions undermine investments.•The farmers may benefit from achieving a part of the downstream price premiums.