We consider social choice problems where a society must choose a subset from a set of objects. Specifically, we characterize the families of strategy-proof voting procedures when not all possible subsets of objects are feasible, and voters' preferences are separable or additively representable.

Thinking about Ronald Coase, economists generally refer to transaction and social costs, to the importance of property rights and institutions or to the Coase-theorem. Examine his work more closely, a common feature takes shape behind these ideas, the public utilities. The constant and detailed...

Several decades of market opening has become a characteristic of network industries. Its main hindrances and aids has come into sight during this period. There is a need now to evaluate the process of market opening and to assess the steps to be taken. Market opening is usually measured by...