ABSTRACT
In Chapter 6, we saw that Friedman’s ‘as if’ methodology was embraced by economists for two reasons. First, Friedman relieved economists of any worries about the reality content of the assumptions on which their theories were based. His concept of research confirmed what economists had regarded as characteristic of their discipline ever since Mill: economics was not an experimental science, so economists needed to use other criteria for constructing theories and testing them. But whereas Mill relied on a kind of inner experiment in testing the validity of the assumptions underlying his theories, Friedman showed that the validity of assumptions was irrelevant. Economics was not alone in relying on assumptions that everyone knew from the start to be unrealistic; disciplines such as astronomy and biology did the same. This did not make their theories any less workable. The usefulness of economic theories could be measured by their power to make accurate predictions.
