Most institutional investors in the early 1970s, on the other hand, regarded business value as of only minor relevance when they were deciding prices at which they would buy or sell. This now seems hard to believe. However, these institutions were then under the spell of academics at prestigious business schools who were preaching a newly-fashioned theory : the stock market was totally efficient, and therefore calculations of business value – and even thought, itself – were of no more importance in investment activities. (we are enormously indebted to these academics : what could be more advantageous in an intellectual contest – whether it be bridge, chess, or stock selection – than to have opponents who have been taught that thinking is a waste of energy?)