Redistribution is one of the most fundamental issues in welfare economics. In connection with this term the following questions directly arise: What is a good redistribution ? Which (governmental) instruments should be used to attain it ? Is there a "best instrument" if several of them are available? Or, to express it more generally, which allocations are at all attainable if special instruments are at hand ? All these questions are formulated in an extremely vague way. It will be the task of the following work to make these questions precise and to give answers - as far as possible. It is a...