Journal article: The recessions during the periods in the 1930s and starting in 2008 are compared on two points : a) public authorities’ reactions at the peak of these two banking and financial crises (which differed significantly thanks to what both the United States and Europe had learned during the Great Depression) ; and b) the financial regulations adopted in reaction to the 2008 meltdown. In the main, the regulations adopted during the Great Depression were gradually lifted between the 1950s and 1990s, thus doing away with many inconsistences and sources of inefficiency but also recreating considerable fragility – as became apparent in 2008. Owing to the political and scientific context, the long stagnation after 2008 has not (yet) set off a regulatory trend on as large a scale as during the Great Depression.