The Maastricht Treaty (in Article 109j) requires the Commission and the European Monetary Institute to assess Member States' compliance with the convergence criteria, including a number of other conditions (including central bank independence). These reports, including the Commission's recommendations, formed the basis for the decision on the list of participating countries made by the Heads of State or Government on 2 May 1998. The Commission and the EMI published their reports on 25 March. At the same time, the Commission recommended 11 countries that had achieved the necessary high level of sustainable convergence for successful participation in the euro from 1 January 1999.