In the analysis by Roll, "computer-designed trading" is judged to have been present in five of the 23 national markets examined: Canada, France, Japan, U.K., and U.S. (Roll 1988, pp. 29-30). This judgment, however, masks large differences in scale. For example, the Bank of England reported that: "In contrast to the US markets, the use of stock-related derivative products in the United Kingdom is very limited and the volume of stock-index-related business is very small" (Anonymous 1988a, p. 58).

Donald MacKenzie, An Engine, Not a Camera, loc. 1576