What is the principal source of profits – Part Two

Continuing from my last post is the never-ending discussion of which factors drives organizational profitability. As mentioned earlier, the relative importance of industry in this context has been challenged by a series of studies in the later years.

For the sake of clarity: Such empirical studies take a large sample of firms and compare the extent to which variance in profitability is due to firms or industry (controlling for other effects). If firms within the same industry tend to bunch together in terms of profitability, it is industry that is accounting for the greater proportion of profitability and an external approach to strategy is therefore supported. The chief advocate of such an external approach is of course the well-known Michael Porter.

If firms within the same industry vary widely in terms of profitability, it is the specific skills and resources of the firms that matter most, and naturally an internal approach is most appropriate. An influential study of this was done by Richard Rumelt in 1991, and since world-famous strategists and researchers still haven’t come to some sort of conclusion, I am going to keep it all simple by comparing the two important studies done by Rumelt and Porter & McGahan.

As we can see, the two most important studies find that more of the variance in organizational profitability is due to firms rather than industries; in Rumelt’s study the organization’s resources, capabilities, structure and so on, counts for 47 % while Porter & McGagan suggest that the firm accounts for 31 %, but with higher industry effect as well (19 per cent)

It should also be noted that Roquebert, Phillips and Westfall published a meta anslysis where they compared Rumelt’s analysis up against Richard Schmalensee’s analysis from 1985. Their research does not only confirm most of Rumelt’s findings, but also suggest the existence of a corporate effect. If you have access to the Strategic Management Journal, it is a highly recommended read (Vol 17, pp. 653-664 (1996))

Such discussions will probably go on, but it will be interesting to see how the environmental changes in recent years (especially technology development, shorter life cycles and so on) will affect these factors in the future.