The EMH has nothing to do with the "rationality" of individual market participants, it is the statistical result of a very large number of mutually agreeable transactions made with fairly complete information. In what way could "behavioural finance" possibly undermine an argument about statistical market efficiency?

2. Financial markets are not responsible for government over-borrowing, any more than your bank forces you to take out a car loan unless you want to. It is nevertheless true that investment banks will help governments to borrow if the latter want to. In the end, it is always the citizen who pays the penalty. If we wanted to stop our government from borrowing excessively, what could we do that might actually work in the long term? Make sure to give some concrete evidence!

3. Some people think that financial market transactions should be taxed. What are the arguments for and against? Would that really somehow make the world a better place? Or would it just make it even harder for you to save for your retirement?