But a theory is not like an airline or bus timetable. We are not interested simply in the accuracy of its predictions. A theory also serves as a base for thinking. It helps us to understand what is going on by enabling us to organize our thoughts. Faced with a choice between a theory which predicts well but gives us little insight into how the system works and one which gives us this insight but predicts badly, I would choose the latter, and I am inclined to think that most economists would do the same.
Economics thus becomes a convenient instrument the state uses to manage the economy, rather than a tool the public turns to for enlightenment about how the economy operates. But because it is no longer firmly grounded in systematic empirical investigation of the working of the economy, it is hardly up to the task. During most of human history, households and tribes largely lived on their own subsistence economy; their connections to one another and the outside world were tenuous and intermittent. This changed completely with the rise of the commercial society. Today, a modern market economy with its ever-finer division of labor depends on a constantly expanding network of trade. It requires an intricate web of social institutions to coordinate the working of markets and firms across various boundaries. At a time when the modern economy is becoming increasingly institutions-intensive, the reduction of economics to price theory is troubling enough. It is suicidal for the field to slide into a hard science of choice, ignoring the influences of society, history, culture, and politics on the working of the economy.