Graham Declines to Predict Earnings

In The Intelligent Investor, Graham evaluated the investment merit of several stocks, but not once did he predict earnings for those stocks. (On other occasions, however, he did venture to predict earnings.) For instance, at the conclusion of his analyses of ELTRA and Emhart stocks, he concluded, "We make no predictions about the future earnings performance. . ." 

That Graham, an eminent security analyst, should decline to predict earnings is intriguing. He obviously did not have much confidence in his ability to predict earnings - nor in others' predictions, especially long-term predictions. Sophisticated investors have always been aware of this difficulty. For instance, John Maynard Keynes, the brilliant British economist, more than a half-century ago emphasized the great difficulty involved in forecasting investment returns. In regard to this difficulty, Keynes said : "The outstanding fact is the extreme precariousness of the basis of knowledge on which our estimates of prospective yield have to be made. Our knowledge of the factors which will govern the yield of an investment some years hence is usually very slight and often negligible. If we speak frankly, we have to admit that our basis of knowledge for estimating the yield ten years hence of a railway, a copper mine, a textile factory, the goodwill of a patent medicine, an Atlantic liner, a building in the City of London amounts to little and sometimes to nothing; or even five years hence. In fact, those who seriously attempt to make such estimates are often so much in the minority that their behavior does not govern the market. "
Apparently because of such problems, Graham believed that the security valuation process is not very reliable. After discussing some problems valuing ALCOA, Graham said, "ALCOA is surely a representative industrial company of huge size. . .[it] supports to some degree, the doubts we expressed [earlier] as to the dependability of the appraisal process when applied to the typical industrial company." 

Because the appraisal process is unreliable, it is prudent to diversify one's investments. Perhaps it is enough, Graham thought, for an investor to be assured that he or she is getting good value, even if an accurate valuation is impossible. 

Finally, the inherent inaccuracy of this valuation process may explain Graham's observation that he had never ". . . seen dependable calculations made about common-stock values . . . that went beyond simple arithmetic or the most elementary algebra." In valuing stock, crude, simple calculations often are as good as you can do.