It seems to me that  4  I. Fisher, “The debt-deflation theory of great depressions”, Econometrica, 1, 4, 1933. 5  M. Casiraghi and G. Ferrero, “Is deflation good or bad?
Just mind the inflation gap”, Banca d’Italia, Questioni di economia e finanza (Occasional Papers), 268, 2015; C. Borio, M. Erdem, A. Filardo and B. Hofmann, “The costs of deflations: a historical perspective”, BIS Quarterly Review, March 2015. 6  S. Neri and A. Notarpietro, “Inflation, debt and the zero lower bound”, Banca d’Italia, Questioni di economia e finanza (Occasional Papers), 242, 2014.