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这个在演化经济学中的文章读到过，以下便是：
In practice 1: Weak Counterfactuals and Appreciative Theory

Counterfactual analysis can be used to buttress appreciative theory. The aim of appreciative theory is less to formalize general laws, which could be used in predicting the future, than to use general, well-understood theoretical concepts to understand either the past or the present. Evolutionary economics takes almost as a precept the idea that understanding is necessarily historical. Thus to understand the present we must know and understand the history that brought us here. History can be seen as a tree--we follow the structure up the trunk, moving onto different branches, but never moving down. As time passes, the economy is continually eliminating future branches, and thereby producing the present. Understanding this process involves showing either that there were no branching points, and thus the present state is inevitable given the starting point, or identifying the branching points (those at which there was a non-trivial probability of taking a different route), and showing why the economy followed the route it did.

We refer to this exercise as one of weak counterfactual history, since it involves minimal knowledge or assertions about the non-actual branches. In this regard it is only necessary to argue that the branches not taken would lead to a different present. Even more generally, weak counterfactual analysis is restricted to understanding the major events and chains of decisions which, coupled with processes that magnified rather than damped their effects, can be considered as having played a role in disconnecting some sub-regions of the tree from the branches followed by actual history.

Advantages of a weak counterfactual argument are clear. Accepting its goals renders Elster's conditions less important, and thus permits economists to treat a large number of problems in those terms. Drawbacks also seem clear however. Weak counterfactual analysis does not give welfare results, and in a sense can only argue that the actual outcome is not the only possible one. This does permit the claim of potential regret, but cannot assert more; it will not make a case for actual regret. (See Foray, 1997.) For that we need something stronger.

3# 亘心
很强大啊   谢谢