Two weeks ago I visited Flowers on the Avenue to buy a dozen roses for my wife. All fall silks were on sale for 50% off. I knew if I waited a week, the silks would be 75% off the following week. so I saved my money and waited a week. That's how a deflationary spiral begins. If prices fall, then wages will fall. The spiral will find a bottom some time after millions have lost their jobs and incomes have fallen. The costs of borrowing increase since debtors are repaying loans with dearer dollars. A graph is here along with a tutorial.