Income is conventionally denoted by "Y" in economics. John Hicks employed "I" for income, but Keynes wrote to him in 1937, "immediately after seeking both equally, I think it is much easier to use Y for income And that i for financial investment. This report presents details on income, earnings, https://income-streams12837.timeblog.net/71031980/the-2-minute-rule-for-income