The banking union is a system of European institutions which, since its inception in November 2014, has comprised a Single Supervisory Mechanism (SSM) and, since the beginning of 2016, a Single Resolution Mechanism (SRM). It also has the purpose of enhancing harmonisation among national deposit guarantee schemes and, at a later date, of possibly comprising a common European deposit insurance scheme (EDIS). All euro area countries are members of this banking union, which has been implemented in increments since 2014. Other EU countries may also opt in if they wish, though none have done so up to now. The purpose of the banking union is to standardise and improve banking supervision in participating member states, to increase financial stability and to loosen the "doom loop" between financial sector debt and sovereign debt which, in the past, had exacerbated the crisis. To further harmonise the various national deposit guarantee schemes, in April 2014 the recast Deposit Guarantee Scheme Directive was adopted. Implementation in Germany was achieved by means of the Deposit Guarantee Act (Einlagensicherungsgesetz), which came into effect on 3 July 2015. The creation of an EDIS is currently being discussed at EU level.