( smp ) presently amounts to somewhat more than 60 billion euros, which again equates to 3 %. there is no evidence that asset purchases have had any significant impact on average euro - area sovereign bond yields on which euro - area monetary policy must exclusively focus as its main transmission channel. but the smp risks blurring the different responsibilities between fiscal and monetary policy. as the risks associated with the smp outweigh its benefits, these securities purchases should now be phased out permanently as part of our non - standard policy measures. 3. current and future challenges for monetary policy 3. 1 exit from exceptional policy measures the challenge facing monetary policymakers now and in the near future is to get the timing and sequencing of the exit from stimulus measures right. this applies to both the nonstandard measures as well as the monetary policy stance, and therefore, key interest rates, as the two dimensions of the exit. while we are far from declaring the crisis over, it would be unwise to postpone relevant considerations to the end of the crisis. as regards the eurosystem ’ s set of non - standard policy measures, these were designed with exit considerations in mind. the overwhelming majority of measures can therefore be easily withdrawn whenever we deem it necessary. as regards the two dimensions of exit consisting of phasing - out non - standard liquidity measures and normalizing our clearly expansionary policy stance, there are risks both in exiting too early and in exiting too late. i believe the latter are greater than the former. for example, maintaining the accommodative policy stance for too long may risk a de - anchoring of inflation expectations, which is costly to reign in. for the time being, however, the policy stance remains appropriate, since inflation risks remain low over the policy - relevant horizon. the two dimensions of exit are independent and separated by concept. thus, a normalization of key interest rates could in principle start before the phasing - out of nonstandard measures has been finished. the phasing - out of non - standard measures mainly depends on the situation in the financial markets and the interbank money market, in particular. while improved conditions enabled us to embark on a gradual phasing - out of exceptional policy measures at the end of 2009, renewed financial market tensions in early may forced us to reintroduce some measures that had already been phased out. looking ahead, the situation in the financial markets shows continuing signs of normalization –

despite some remaining volatility and fragility. against this background, it is necessary, from a monetary policy point of view, not to postpone the exit from non - standard measures for too long, in particular since we always emphasized it would be a state - contingent process. before i discuss the challenges of the phasing - out in more detail, let me briefly recall some key aspects of our monetary policy implementation. in the euro area, the bulk of liquidity is provided via revolving refinancing operations ( collateralized lending ) of different maturities, with the main refinancing operation, that is the one week operation, being the most important. prior to october 2008, refinancing operations were conducted as variable rate tenders, with allotment amounts closely aligned with the aggregate liquidity needs of the banking system ( often referred to as “ benchmark allotment ” ). conceptually, the liquidity needs of the banking system mainly result from non - banks ’ demand for banknotes and substantial remunerated reserve requirements. the particular tender procedure means that average short - term money market rates are normally just slightly above the minimum bid rate in the weekly main refinancing operation, which serves as the key policy rate. however, in october 2008, the variable rate tender procedure with benchmark allotment was replaced by a fixed rate full - allotment procedure, in order to ensure banks ’ liquidity despite the drying up of the interbank money market following the lehman collapse. the full allotment policy allowed banks to accumulate substantial amounts of surplus liquidity ( or excess reserves to use u. s. terminology ), which could be lent to other banks or placed in the eurosystem ’ s deposit facility – an overnight facility to deposit excess reserves. as a result, short - term money market rates usually traded only a couple of basis points above the eurosystem deposit rate throughout most of 2009 and 2010. this was by design. meanwhile, given an ongoing normalization in financial markets, money market rates have increased significantly but smoothly without any monetary policy tightening signals and the corresponding headlines. despite the overall improvements in financial market and money market conditions, some financial institutions, however, continue to rely strongly on the liquidity support measures provided by the eurosystem. in principle, the strong demand for central bank liquidity from these eurosystem counterparties could lead to elevated tender spreads after the return to a variable rate tender procedure.