After the global financial crisis, the overnight repo rate was for a while persistently higher than the overnight Fed Funds rate, whereas previously it had been lower. Which of the following is NOT a possible explanation?

1. Eurodollars sold at a premium
2. Before the crisis, the Fed was trying to encourage borrowing at the Fed Funds rate to expand short term credit
3. After the crisis, default risk was no longer priced positively
4. After the crisis, the Fed was generally trying to foster elasticity by keeping the better money at a discount
5. Before the crisis, the Fed was generally trying to impose discipline by keeping the better money at a premium