This paper formulates a legal-economics nexus of the AD and CVD laws and provides an alternative to the methodology of injury investigation (trend analysis) used by most national authorities in countries which are WTO signatories. The nexus suggested in this paper shows that the magnitude of injury caused by dumping is determined primarily by the degree of price undercutting, and the product and market characteristics of the goods, and the initial conditions of the relevant market. The magnitude of injury (measured by price erosion, output displacement, revenue loss, etc.) can be readily quantified using a simulation model based on economic theory. The validity of adding economic analysis to the legal framework in AD and CVD investigations is clearly demonstrated.