Every year, the estimated growth of macroeconomic aggregates is updated against the previous three years to take into account any new information that has become available since the previous publication. Since 15 May 2014, all aggregates after 1949 have been modified. The national accounts have in fact changed their “base year” and have now moved to the 2010 base, mainly to implement the new version of the European System of Accounts, ESA 2010. These regulations have introduced some important conceptual innovations covering mainly the scope of investment (especially intangible investment), the recording of foreign trade and the description of the activity of insurance companies. They are applicable in all European countries from September 2014. Switching base also means reviewing the methods, classifications and statistical sources used in national accounting, to ensure that they continue to reflect economic reality in the best way possible. This report describes the main changes that have been made and their repercussions for the national accounts. One such change is that the key aggregate in national accounting, gross domestic product (GDP), was revised substantially upwards, mainly due to research and development (R&D) expenditure being treated as investment.