An Examination of Theoretical Predictions of the Strength of Economic Forces.

有时，强大的政府似乎被超出其控制能力的经济力量所控制：例如，在24小时内，英国政府将利率提高到天文数字水平，并发誓在任何情况下都不会让英镑贬值，结果恰恰是这样做了。在其他时候，政策上看似微不足道的小修小补可能会带来深刻的、计划外的变化：例如，前苏联的巨大变化似乎是由戈尔巴乔夫在80年代中期推出的相对温和的政治改革引发的。尽管没有得到广泛的认可，但经济理论预测，在某些情况下，经济力量将是压倒性的强大，而在其他时候，经济力量将非常弱，容易受到操纵。事实上，该理论可以对经济力量的强度做出定量预测。在某种程度上，这些预测是正确的，它们具有巨大的价值，将我们的注意力引导到政策可以真正产生影响的那些类型的问题和情况上。这项研究有两个广泛的目标：第一，使用实验经济学的数据来验证该理论，第二，推进该理论，以提高其在评估经济力量疲软情况下的预测能力。经济学中的实验数据非常复杂：有时理论预测得非常好，有时会出现奇怪的异常，往往会随着实验设计看似微不足道的修改而发生变化。没有仔细研究的是，这些异常现象在多大程度上与所涉及的经济力量有关。我们的假设是，当经济力量强大时，该理论可以很好地预测，而当经济力量较弱时，它预测得很差。这项研究计划回顾一系列广泛的经济实验，以努力确定异常现象是否源于经济力量的疲软。就目前的情况而言，这证实了当前理论能够以一种有用的方式评估经济力量强度的观点。不幸的是，我们的假设的一个含义是，理论所作的预测在政策变化的后果最深远的时候将是最弱的。许多经济学家认为，在这种情况下，个人的学习和适应能力发挥着重要作用。(前苏联正在发生的变化显然就是这种情况。)这项研究的第二个主要组成部分是检验学习的理论后果，以及这种理论做出的预测的类型。其目标是开发有用的数学近似来进行定量预测。

At times powerful governments seem to be seized by economic forces beyond their ability to control: during a twenty-four hour period, for example, the British government raised interest rates to astronomical levels, swearing under no circumstances to devalue the pound, only to do exactly that. At other times, seemingly minor tinkering with policy can unleash profound and unplanned change: the enormous changes in the former Soviet Union, for example, seem to have been triggered by relatively mild political reforms introduced by Gorbachev in the mid-eighties. Although it is not widely recognized, economic theory predicts that under certain circumstances economic forces will be overpoweringly strong, and at other times extremely weak and susceptible to manipulation. Indeed, the theory can make quantitative predictions about the strength of economic forces. To the extent that such predictions are correct, they are of great value, directing our attention to those types of problems and situations where policy can make a real difference. There are two broad goals of this research: first to use data from experimental economics to validate the theory, and second, to advance the theory to improve its predictive power in assessing situations where economic forces are weak. Experimental data in economics is extremely mixed: sometimes the theory predicts extremely well, and at other times strange anomalies occur, often changing with seemingly trivial modifications in experimental design. What has not been examined carefully is the extent to which the anomalies are correlated with the strength of economic forces involved. Our hypothesis is that the theory predicts well when economic forces are strong, and that it predicts poorly when economic forces are weak. This research plans to review a broad cross-section of economic experiments in an effort to determine whether the anomalies are due to the weakness of the economic forces. To the extent that they are, this validates the idea that current theory can assess the strength of economic forces in a useful way. Unfortunately, an implication of our hypothesis is that predictions made by theory will be weakest exactly when the consequences of policy changes will be most profound. Many economists feel that under these circumstances, the ability of individuals to learn and adapt plays an important role. (This is clearly the case in the changes unfolding in the former Soviet Union.) The second major component of this research is to examine the theoretical consequences of learning, and the types of predictions such a theory makes. The goal is to develop useful mathematical approximations for making quantitative predictions.