From Paul Volcker, interviewed by Martin Feldstein in the Journal of Economic Perspectives.

[Early in 1980, President] Carter was obviously under pressure, so he triggered a provision of law that
permitted the Federal Reserve to put on credit controls…We said, “Okay, you’re going to have a reserve requirement on credit cards—if credit cards exceed past peaks, you would have a reserve requirement.” We did that knowing, we’re now in March, the peak in credit card use comes in November and December. We were way below it so there was no possibility that this was going to become a factor for some time…The economy at that point fell like a rock. People were cutting up credit cards, sending in the pieces to the President as their patriotic duty. Mobile home and automobile sales dropped within the space of a week or so. The money supply, we didn’t know why the money supply was dropping, but all of the sudden the money supply was down 3 percent in a week or something…Well, it was a recession alright, the economy went down, but it was an artificial recession. As soon as we took off the credit controls in June, the economy began expanding again

Credit rationing seems to be quite powerful. Recall that before the late 1980s, interest-rate regulations ensured that when interest-rates rose, the depository institutions would find themselves without money to lend for mortgages, and that was usually enough to bring about a recession.