Researchers may download the Bryce-Winter relatedness index from this website. The Index was developed at Wharton and the Center for Economic Studies at the Census Bureau by David Bryce (now at BYU) and Sidney Winter as a tool for relatedness-based research on the scope of the firm. It is made available to researchers here in hopes that it can be useful in other research and also because its construction is complex and time consuming.

The index is constructed using patterns of industrial diversification as they existed in the manufacturing sector in 1987. The reference categories for the measure are the 1987 Standard Industrial Classification (SIC) system four-digit definitions (codes 2000-3999 only). Every possible pair of four-digit industry combinations is represented, excluding only same-digit pairs, pairs with catch-all industries labelled ‘not elsewhere classified’ (n.e.c.), and pairs in which no firm operated in one of the industries. (Please note that this is different than saying no diversified firm operated in both industries in a pair-a case for which scores are included).

A paper motivating the measure and describing the technique for its construction can be accessed here.

Citation:

Bryce, David J. and Sidney Winter. 2009. A general interindustry relatedness index. Management Science 55(9): 1570-1585.