The introduction sets out the different types of causal relationships that the law of the World Trade Organization (WTO) raises. It also defines both causation and non-attribution in the law of the WTO and discusses the fact that both are required in this legal context. The introduction foreshadows the contents of each of the five substantive chapters that follow. It explains the concept of the Tripartite Non-attribution/Causal Link Approach and discusses the advantages and disadvantages of taking an econometric approach to analysing causation. The introduction also explicates those causal questions in WTO law that fall outside the scope of the book as it explains why they do not fit with the concept of the Tripartite Non-attribution/Causal Link Approach. The introduction also explores some of the limitations of the book as well as containing a brief discussion of the sources and methodology of the book.