In an industry setting, classic supply chains display strict hierarchy, whereas clusters of firms have linkages going in many different directions. Previous theory has often assumed the existence of the hierarchical relationships among firms and empirical work has focused on a single level of an industry or bilateral relationships. However, quantitative evidence on the deep hierarchy in large industrial sectors is lacking. In this paper, we develop metrics and methods to define and measure the degree of hierarchy in transactional relationships among firms, and apply the methods to two large industrial sectors in Japan: automotive and electronics. Our empirical analysis shows that the automotive sector exhibits a higher degree of hierarchy than the electronics sector. The empirical measurement and model analysis together indicate that it is the low transaction specificity that drives down the degree of hierarchy in the electronics sector. Differences in transaction patterns in turn may result from the differences in the power level of underlying technologies, which affect product specificity and asset specificity. Thus, the degree of hierarchy in an industry sector may be traced back to fundamental properties of the underlying technologies.