##ties and parameters of intervention were adapted to local circumstances, such as the depth and liquidity of financial markets and the degree of intermediation in the financing of the economy, which differ considerably across major economies. some would argue that it is likely that most of the new instruments may not be needed to the same extent once money market conditions – and more generally the transmission channels of monetary policy – return to normal. but is it so likely? this immediately brings up the question that the panel is posing : “ where to exit to? ”. we may want to ask ourselves which elements of our current mode of operation have served us well, and not only as a crisis management tool, and may therefore survive as a more permanent feature of the new steady state. so, let me share some thoughts on what remains unresolved about the issues that i mentioned at the start. i see four open questions, and i want to be very honest : i will not give answers. first question : the size and degree of symmetry of the interest rate corridor. second question : the duration and maturity of central bank operations. third question : the mode of the liquidity provision to banks. and fourth, the shifts in amplitude and quality of collateral pools, and the risk management implications associated with these shifts. let me start by discussing the interest rate corridor. as i mentioned already, the ecb entered the crisis with a tradition of conducting policy through a corridor – others would say, a “ channel ” – system. the ecb ’ s corridor is determined by the two overnight standing facilities : the marginal lending facility and the deposit facility. these standing facilities were set symmetrically around the main policy rate charged on central bank credit at the weekly refinancing operations. prior to the crisis, the quantity provision at our weekly operations was calibrated in such a way that, given banks ’ liquidity needs, the overnight money market rate would settle close to the policy rate. so, the corridor was symmetric de jure and de facto : liquidity volumes were just sufficient to validate the mid - point of the corridor as the price of liquidity to which market overnight rates would gravitate on average. at the onset of the crisis, we moved quickly from a system of liquidity provision geared towards filling the system ’ s liquidity deficit towards a set - up in which banks operate under aggregate excess liquidity. so, following the shift to a fixed - rate full allotment mode of liquidity provision in

luis de guindos : building a resilient economic and monetary union lectio magistralis by mr luis de guindos, vice - president of the european central bank, opening the xxix edition of the masters programme in european union law of the university carlos iii of madrid, madrid, 5 october 2018. * * * the crisis, its aftermath and the road to recovery this autumn marks ten years since the start of the global financial crisis. it was a seismic event that laid bare a number of weaknesses in the international financial system – and in the oversight of that system. in its wake, it also revealed profound shortcomings in the architecture of economic and monetary union ( emu ) which, ultimately, resulted in the global financial crisis morphing into a euro area crisis – and pushing many parts of europe into a second recession. thankfully, the experiences of the past decade have prompted a strengthening of the regulations and the establishment of institutions with the necessary instruments to ensure stability. at global level this took the form of stronger regulation and cross - border cooperation. at european level, it meant a multi - dimensional reform of emu : financial, fiscal, economic and even political. as a result, and supported by the ecb ’ s monetary policy, the euro area returned to growth in 2013, and has created more than nine million jobs since then. we have come a long way. but there can be little doubt that we are still feeling the effects of the crisis and are still addressing some of the underlying fault lines. it ’ s an important task, but it seems that it is no longer being pursued with the same sense of urgency. that is why, today, i want to take this opportunity to highlight areas where we need to continue to push forward and put emu on a more sustainable footing. after briefly reviewing the progress already made, i will argue that the current debate on deepening our monetary union requires three main elements to ensure the long - term viability of the european project. first, we need to remain ambitious in completing the banking union so as to safeguard financial stability. second, we need to revamp our fiscal rules and create a stabilisation instrument to enhance the resilience of the monetary union as a whole. third, we need to bolster long - term economic growth by implementing structural reforms and harnessing the potential of europe ’ s single market. responding to, and learning from, the crisis in order to get a clearer idea of the