Thank you for your reply The source is the article the Hanke Krus Hyperinflation Table is based on Cagan s definition Section 4 is based on Cagan s definition 100 copied from the Hanke Krus Table Section 5 is based on Cagan s definition Section 6 is based on Cagan s definition Section 7 is based on Cagan s definition The Hanke Krus Hyperinflation Table is based on Cagan s definition The table is itself externally linked in the article Please see the table Prof Steve Hanke is the number one expert in the world on hyperinflation See the external links on his article page That should surely be more than enough external sources for the fact that Cagan s definition is the generally accepted definition of hyperinflation because Prof Steve Hanke uses it as shown in the table and in all the sub sections in the article This clearly demonstrates the external sources that there is no doubt that Cagan s definition is the generally accepted definition of hyperinflation All governments follow Cagan s definition