During early December, the European Central Bank adopted powerful unprecedented policy measures, as it implemented the long-term refinancing operation program and broadened the scope of acceptable collateral. This program has averted a full-blown liquidity crisis, given that it eased rollover funding pressures on many banks.
Moreover, from the perspective of policy makers, it is considered highly important  5  to foster a better understanding of changes in market structure not only for market analyses in normal times, but also for assessing the situation in times of crises and considering countermeasures. III.