The average portfolio structure of institutional investors is shown to reproduce the structure which optimally accounts for transaction costs when investment constraints are weak. Strikingly, this result emerges even though these investors are not aware of the existence of such law and despite the fact that their aims and tools are very heterogeneous. This extends the so-called wisdom of the crowd to much more complex situations in two important ways. First, wisdom of the crowd also holds for whole functions instead of a point-wise estimates. Second, this shows that in socio-economic systems, the optimal individual choice may only be found when the diversity of individual decisions is averaged out. Thus, rationality at a collective level does not need nearly rational individuals with well-aligned incentives. Finally we discuss the importance of accounting for constraints when assessing the presence of wisdom of the crowd.

研究表明，机构投资者的平均投资组合结构可以再现这种结构，当投资约束条件较弱时，该结构可以最佳地说明交易成本。令人惊讶的是，即使这些投资者不知道该法律的存在，尽管他们的目标和工具非常不同，但仍会出现这种结果。这通过两种重要方式将所谓的人群智慧扩展到更为复杂的情况。首先，人群的智慧也可以代替整个功能，而不是进行逐点估计。其次，这表明在社会经济系统中，只有在平均个体决策的多样性时才能找到最佳的个体选择。因此，集体层面的理性并不需要具有合理动机的近乎理性的个体。