 Cover of mass market edition by Anchor | |
| Author | James Surowiecki |
|---|---|
| Language | English |
| Publisher | Doubleday; Anchor |
Publication date | 2004 |
| Publication place | United States |
| Pages | 336 |
| ISBN | 978-0-385-50386-0 |
| OCLC | 61254310 |
| 303.3/8 22 | |
| LC Class | JC328.2 .S87 2005 |
The Wisdom of Crowds: Why the Many Are Smarter Than the Few and How Collective Wisdom Shapes Business, Economies, Societies and Nations, published in 2004, is a book written by James Surowiecki about the aggregation of information in groups, resulting in decisions that, he argues, are often better than could have been made by any single member of the group. The book presents numerous case studies and anecdotes to illustrate its argument, and touches on several fields, primarily economics and psychology.
The opening anecdote relates Francis Galton's surprise that the crowd at a county fair accurately guessed the weight of an ox when their individual guesses were averaged (the average was closer to the ox's true butchered weight than the estimates of most crowd members).[1][2]
The book relates to diverse collections of independently deciding individuals, rather than crowd psychology as traditionally understood. Its central thesis, that a diverse collection of independently deciding individuals is likely to make certain types of decisions and predictions better than individuals or even experts, draws many parallels with statistical sampling; however, there is little overt discussion of statistics in the book.
Its title is an allusion to Charles Mackay's Extraordinary Popular Delusions and the Madness of Crowds, published in 1841.[3]
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Introduction (p. XII): Although Surowiecki's description of the "averaging" calculation (p. XIII) implies that Galton first calculated the mean, inspection of the original 1907 paper indicates that Galton considered the median the best reflection of the crowd's estimate. (Galton, Francis (1907-03-07). "Vox Populi". Nature. 75 (1949): 450–451. Bibcode:1907Natur..75..450G. doi:10.1038/075450a0. S2CID 4013898.
the middlemost estimate expresses the vox populi
). Galton's quotation from the end of this paper (given by Surowiecki on page XIII) actually refers to the surprising proximity of the median and the measurement, and not to the (much closer) agreement of mean and measurement (which is the context Surowiecki gives it in). The mean (only 1 pound, rather than 9, from the ox's weight) was only calculated in Galton's subsequent reply to a letter from a reader, though he still advocates use of the median over any of the "several kinds" of mean (Galton, Francis (1907-03-28). "Letters to the Editor: The Ballot-Box". Nature. 75 (1952): 509. doi:10.1038/075509e0. S2CID 3996739.my proposal that juries should openly adopt the median when estimating damages, and councils when estimating money grants, has independent merits of its own
); he thinks the median, which is analogous to the 50% +1 vote, particularly democratic. - ^ Recent research in the Galton Archive at University College, London, has found some small discrepancies between the original data and the results printed in Galton's articles, such that the mean estimate exactly coincides with the correct weight of the dressed ox. Had he known the true outcome, Surowiecki's conclusion on the wisdom of the Plymouth crowd would no doubt have been more strongly expressed. (Wallis, K.F. (2014), "Revisiting Francis Galton's forecasting competition", Statistical Science, 29, 420–424. doi:10.1214/14-STS468.)
- ^ Surowiecki, James (2005). The Wisdom of Crowds. Anchor Books. pp. xv. ISBN 978-0-385-72170-7.