| We study social choice in various economic environments. Our purpose is to seek for solutions or social orderings that satisfy certain normative requirements such as efficiency or fairness. We conduct our search for four types of problems: locating an undesirable facility and sharing its cost; allocating indivisible goods and money; ranking allocations of perfectly divisible goods; ranking intergenerational consumption paths in dynamic economies with infinite generations.; Chapter 1 is an introduction.; In Chapter 2, we consider the problem of locating a facility that no district wants as a neighbor (e.g., a landfill, garbage incinerating facility, or fire power plant), and sharing its cost. Each district is characterized by two parameters, a disutility parameter and a construction cost. The sum of the two parameters is referred to as "total cost". We characterize the class of efficient and monotonic solutions. To each such solution is associated a monotone-path function from the real-line to the utility space. The function fully determines utility allocations according to the lowest total cost. In the class, there is essentially only one symmetric solution. It chooses allocations at which all districts enjoy equal utilities. Though this solution is not completely immune to strategic-manipulation, it satisfies certain "second best" robustness conditions.; In Chapter 3, we introduce a general framework for fair allocation of indivisible objects when each agent can consume at most one (e.g., houses, jobs, positions), and monetary compensations are possible. Here, our objective is to find fair and implementable solutions. We show that the no-envy solution is essentially the only Nash implementable solution that satisfies an horizontal equity requirement.; In Chapter 4, we study social ordering functions in exchange economies with perfectly divisible goods. We show that if a social ordering function satisfies certain Pareto, individual rationality, and local independence conditions, then the set, of top allocations is contained in the set of Walrasian allocations, and all individually rational but non-Walrasian allocations are typically ranked indifferently. The Walrasian solution can be regarded as the social ordering function whose indifference classes are the set of Walrasian allocations and the set of remaining allocations. Hence, such a social ordering function is quite similar to the Walrasian solution.; In Chapter 5, we examine the existence of equitable preferences on intergenerational consumption paths in an infinite horizon setting. Inequality aversion in allocations and equality in treating generations are the main ethical considerations that capture the concept of intergenerational equity. We investigate the existence of binary relations that satisfy these requirements as well as other standard axioms, such as monotonicity, transitivity, or continuity. We show that any domain admitting such a binary relation is quite restricted: its interior is empty and contains no sustainable consumption path. |
