A set of n objects and an amount M of money is to be distributed among m people. Example: the objects are tasks and the money is compensation from a fixed budget. An elementary argument via constrained optimization shows that for M sufficiently large the set of efficient, envy free allocations...

Due to computing and communication facilities, formal procedures, often referred to as "algorithms," are now extensively used in public, economic, and social areas. These procedures, currently at the forefront of criticisms, share some features with mechanisms as defined by economists, following...