the balance sheet. see, for example, armas, a. and singh, m. ( 2022 ), “ digital money and central banks balance sheet ”, imf working paper, no 206. 9. the corridor consisted of a marginal lending facility which provided a daily backstop for banks facing unanticipated liquidity shocks and a deposit facility rate. in 2003, the governing council decided to reduce the maturity of the mros from two weeks to one week and to adjust the timing of the reserve maintenance period. see ecb ( 2003 ), “ measures to improve the efficiency of the operational framework for monetary policy ”, 23 january. 10. anbil et al., ( 2020 ), “ what happened in money markets in september 2019? ”, feds notes, 27 february ; and federal reserve system ( 2019 ), august 2019 senior financial officer survey. 11. banks were required to fulfil their reserve requirements on average during the maintenance period. this reduced the need for recourse to the standing facilities during the maintenance period. however, by design the facilities were systematically and intensely used on the last day of each maintenance period if there was an aggregate shortage or excess of reserves. 12. see kim, k., martin, a. and nosal, e. ( 2020 ), “ can the u. s. interbank market be revived? ”, journal of money, credit and banking, vol. 52 ( 7 ), pp. 1645 - 89 ; and afonso, g., armenter, r. and lester, b. ( 2019 ), “ a model of the federal funds market : yesterday, today, and tomorrow ”, review of economic dynamics, vol. 33, pp. 177 - 204. for a long time, an efficient interbank market was associated with hopes of increased financial stability through counterparty monitoring ( see, for example, rochet, j - c. and tirole, j. ( 1996 ), “ interbank lending and systemic risk ”, journal of money, credit and banking, vol. 28 ( 4 ), part 2 : payment systems research and public policy risk, efficiency, and innovation, pp. 733 - 762 ). however, the global financial crisis may have permanently extinguished these hopes, probably because banks do not have strong incentives to monitor the solvency of their counterparties when most borrowing activity takes place overnight. 13. before 2008, the width of the corridor in

peter praet : creating an enabling environment for pan - european banks in the banking union remarks by mr peter praet, member of the executive board of the european central bank, at the eurofi financial forum 2018, vienna, 5 september 2018. * * * in recent years, the european union has achieved major progress towards financial integration. we now have a single supervisor and a single resolution authority, and banks are subject to the same european rulebook. the banking union contributes to providing effective mechanisms for cross - border risk - sharing and broadening the sources of funding within a country, thereby promoting macroeconomic stability and growth. however, we still observe a number of obstacles that hinder the fungibility of capital and liquidity of banking groups. very often, these obstacles relate to regulatory fragmentation and ring - fencing of national markets. further harmonisation would help to address many of the issues, while appropriate prudential safeguards can be put in place to address possible financial stability concerns by national authorities. first, a number of national options and discretions are hindering the practical application of cross - border liquidity waivers within the union. while such waivers are explicitly allowed by the crr, and already contain prudential safeguards, so far the ecb has received almost no application for their use from the banks it supervises. an important reason for this lack of applications is the existence of national large exposure limits on intragroup exposures in several european countries. these limits prevent institutions in these countries from transferring liquidity within the group in a flexible manner and thus represent practical obstacles to the use of liquidity waivers. effectively, they are hindering the free flow of liquidity in the banking union and should be harmonised further. second, the proposal to have cross - border capital waivers within the eu was not taken forward in the on - going review of the crr, which is a missed opportunity. such waivers would be consistent with the establishment of the ssm and the banking union and help to support the free flow of capital across the union. on the one hand, it is understandable that some national authorities are concerned about the possible financial stability implications of the proposal. on the other hand, such concerns could be addressed by making the waivers subject to additional prudential safeguards, and by putting in place appropriate transition arrangements that account for the planned further progress on the banking union. third, the major progress we have made in our banking union needs to be recognised also in the international