As mentioned,RET does not assume short-term financial market efficiency,only that expectations are not systematically wrong over the long term - but how long is that,and how useful is it to ignore the short term? Many of the approaches to keep RET but not EMH still downplay systemic biases in financial markets. (One view is that if regulation could some how correct the systemic biases identified,there would be market stability.) They underplay the tendency of financial markets to create positive feedbacks,and they fail to capture medium to long-term but identifiable macroeconomic imbalances. They are not good at explaining sudden market fall and structural shifts - defined as discrete non-reversible changes in economic behaviour or economic conditions. Yet structural shifts do occur and to understand them requires some knowledge of macroeconomic imbalances and policies or what used to be called political economy. And short-term events do not always wash out in the long term but can define the long term. History can be path dependent.