"Zimbabwe has barred former U.N. secretary general Kofi Annan and former U.S. President Jimmy Carter visiting the country to assess the humanitarian crisis." One explanation.
"For ordinary Zimbabweans, the consequences are appalling . Their savings destroyed, they must spend money as soon as they obtain it. Supermarkets in Harare are already only accepting US dollars or South African rand."
"The Reserve Bank plans to introduce a number of new, higher denominations; review the cash withdrawal limits, as well as commence aggressive campaigns for increased usage of alternative means of payment."