The French economist Étienne Mantoux criticised the impact of Keynes' book in his book "The Carthaginian Peace: or the Economic Consequences of Mr. Keynes" by saying that it did more than any other writing to discredit the Treaty of Versailles. Mantoux compared "The Economic Consequences of the Peace" to Edmund Burke's "Reflections on the Revolution in France" because of the immediate influence on public opinion. Mantoux sought to discredit Keynes' predictions of what the consequences of the Treaty would be. For example, Keynes believed European output in iron would decrease, but by 1929, iron output in Europe was up 10% from the 1913 figure. Keynes predicted that German iron and steel output would decrease, but by 1927, steel output had increased by 30% and iron output increased by 38% from 1913 (within the pre-war borders). Keynes also argued that German coal mining efficiency would decrease, but labour efficiency by 1929 had increased on the 1913 figure by 30%. Keynes contended that Germany would be unable to export coal immediately, but German net coal exports had grown to 15 million tons within a year and by 1926 the tonnage exported had reached 35 million. Keynes also claimed that German national savings in the years after the treaty would be less than 2 billion marks: however, in 1925, the German national savings figure was estimated at 6.4 billion marks and, in 1927, 7.6 billion marks.