Some of the key reforms introduced include an increase in the quantity and quality of minimum regulatory capital and the creation of capital buffers. New prudential requirements have also been introduced, such as the limits on large exposures, a maximum leverage ratio and two liquidity requirements, at the same time as the reform of the frameworks for evaluating market risk and securitisations has been launched. In addition, last December, a second wave of reforms introduced within the framework of the Basel Accords was completed. The focus of these measures has been the calculation 3/14  of risk-weighted assets, i.e. the denominator of the capital ratio, in order to improve the comparability of capital ratios across banks and jurisdictions. Another lesson of the crisis was that it is necessary to prevent and mitigate the effects of an excessive build-up of risk in the financial system as a whole. An exclusively microprudential based regulatory framework is clearly not sufficient to achieve this. New instruments were considered necessary to help moderate and address cyclical systemic risks (such as, for example, those associated with the credit cycle) and cross-sectional systemic risks (for example, those linked to the risk arising from, among other aspects, the size, complexity and density of the interconnections between financial institutions). With regard to cyclical systemic risks, a countercyclical capital buffer has been introduced, with a view to preventing risks arising from excessive credit growth at the aggregate level.
6/14  It should also be noted that the negative effects of protectionism tend to grow stronger over the long term, owing to the damaging impact of trade barriers on competition, productivity, technological innovation and potential growth. In the present context, characterised by the risk of heightened trade tensions, the review of the world trade negotiation rules and reform of the World Trade Organisation (WTO), the legal basis for the main trade exchanges in recent decades, are of even greater consequence. In fact, from a broader perspective, the latest political reactions against free trade come on top of a deeper, pre-existing crisis in the multilateral trade system. The security provided by trade rules enabled average tariffs between the United States, Europe and Japan to be cut from 22% in 1948 to 3% in 2000. However, in the latest round of negotiations between the WTO member countries, which took place in Doha in 2001, very little progress was made and structural problems currently affecting this system became apparent. These include, notably, the requirement for unanimity among the 164 members of the organisation for the approval of new provisions and the existence of a body of rules that has proved to be inadequate to manage the variety of challenges raised by China’s joining the WTO in 2001. A possible way out of the current crisis in the system of rules for world trade and the WTO that has been recently discussed would involve moving from a multilateral system based on unanimity to a more flexible approach.