This paper deals with the importance of rationing for international trade flows. The analysis is based on a macroeconometric rationing model for the Federal Republic of Germany. Besides a theoretical treatment of various channels through which rationing occurs, an estimation of a rationing model is carried out with special reference to the trade flows. A crucial question concerns the adequate variable which may be able to capture rationing. This paper discusses to what extent that answers from a business survey may be used as proxies for possible rationing.