In just seven years—the seven years of famine—the Egyptians saw their freedoms and economic prerogatives fly away and their lifestyles change dramatically. The first listed casualty of this famine-triggered tribulation was monetary.
The Egyptians were not a bunch of degenerate Bedouins living on the edge, caught in the backwaters of civilization, and laboring under some inefficient and very limiting bartering system. Nothing like that! Rather, as one of the chief nations on the earth at the time, theirs was a complex society with some sort of monetary system. That monetary system completely collapsed due to the repeated crop failures in Egypt.
Joseph's response was to sell Egypt's grain on the spot market. All transactions were cash-and-carry. There was no credit. What occurred was, effectively, centralized control of the money supply. The government came into ownership of all the money, and the people had virtually none at all.
The Other Great Tribulation