In response, the EU tightened the supply in the €40 billion ($50 billion) emissions market, and the price of emission rights was expected to rise by 61% by 30 June 2015 (Carr, 2014). In early 2014 the European Commission published its legislative proposal for a market stability reserve in the EU Emissions Trading System. This measure would enable the Commission to add or remove carbon allowances from the system according to pre-set rules (Yougova, 2015).