The amount by which available supplies are greater than the quantity that will bring producers an adequate income. A surplus may be due to production outrunning demand, a decline in consumption, or a general decline in consumer income or buying power. Historically, commodity programs have been designed to deal with "problems" of surplus, and the Secretary of Agriculture has had discretion to determine whether an item is in surplus and should be removed from market channels to shore up prices. Approaches have included cropland diversion to reduce production, long-term storage of excess supplies, and purchase and donation of surplus items for foreign or domestic food program use.