However, a persistent decline in prices means that the more you wait, the more goods and services you can get at the same price. In other words, it means that the value of cash and deposits increases just by holding them.
Thus, firms and households will hoard money as much as possible and defer actions that are associated with spending, such as consumption and investment. Put in the jargon of economics, aggregate demand will decline. That is a problem. If aggregate demand declines and sales of goods and services decrease, firms will reduce production to a level consistent with the decline in sales.