It therefore reflects in broad terms the structure shown in Figure 2.10. Under the Act, stock assessments are used to trigger regulatory action (Box 2.8). This Act also requires rebuilding to take place within ten years, with some exceptions. While this has been criticised as inflexible, such a deadline has a number of important benefits. It allows compliance with the requirements of the Act to be clearly assessed, it makes the rebuilding target real and enforceable, and low'ers the political transactions costs surrounding identifying the relative importance of stock rebuilding versus near-term economic losses.