Further, EU employment law requires that EU DWF crew receive two months of paid holiday—including transfers— for each four months of work onboard .8 EU DWF crew also receive several days of holiday when the fish is offloaded, whereas crew on Filipino and Taiwanese boats often do the stevedoring themselves (ibid.). This heterogeneity in part contributes to the complexity of analysing the potential implications of proposed fisheries subsidies disciplines at the WTO. First, it is difficult to identify and prove a 'trade distortion' for fish products since the same species normally fetch widely different prices because of complex quality and market differentials. Second, the WTO's analytical emphasis on exchange/ trade means subsidies are defined mainly in terms of export distortions, which the Agreement on Subsidies and Countervailing Measures (ASCM) suggests should be assessed by examining negative trade effects such as market share or prices in an export market.