Many voices have been heard since 2009 on the need to reform the global monetary system. The most prominent ones have been those of the Chinese central bank governor and the Commission of Experts convened by the President of the UN General Assembly on Reform of the International Monetary and Financial System, chaired by Joseph E. Stiglitz. Before the crisis, there were significant concerns about the implications of global imbalances and escalating U.S. net liabilities with the rest of the world, and a heated debate on its implications for global financial stability, but few saw a significant problem in the global monetary system as such.