Consider a society with a finite number of sectors (social issues or commodities). In a partial equilibrium (PE) mechanism a sector authority (SA) aims to elicit agents' preference rankings for outcomes at hand, presuming separability of preferences, while such presumption is false in general and such isolated rankings might be artifacts. This paper studies what can be Nash implemented if we take such misspecification of PE analysis as a given institutional constraint. The objective is to uncover the kinds of complementarity across sectors that this institutional constraint is able to accommodate. Thus, in our implementation model there are several SAs, agents are constrained to submit their rankings to each SA separately and, moreover, SAs cannot communicate with each other. When a social choice rule (SCR) can be Nash implemented by a product set of PE mechanisms, we say that it can be Nash implemented in PE. We identify necessary conditions for SCRs to be Nash implemented in PE and show that they are also sufficient under a domain condition which identifies the kinds of admissible complementarities. Thus, the Nash implementation in PE of SCRs is examined in auction and matching environments.

Noting that a full characterization of Nash-implementation is given using a canonical-mechanism and Maskin's theorem (Maskin, 1999) is shown using a mechanism with Saijo's type of strategy space reduction (Saijo, 1988), this paper fully characterizes the class of Nashimplementable social choice correspondences (SCCs) by mechanisms endowed with Saijo's message space specification -s-mechanisms. This class of SCCs is further shown to be equivalent to the class of Nashimplementable SCCs, though any further 'strategy space reduction' mechanism breaks this equivalent relationship down.JEL classification: C72; D71; D82.

We analyse the implications of classical liberal and libertarian approaches for distributive justice in the context of social welfare orderings. We study an axiom capturing a liberal non-interfering view of society, the Weak Harm Principle, whose roots can be traced back to John Stuart Mill. We show that liberal views of individual autonomy and freedom can provide consistent foundations for welfare judgements. In particular, a liberal non-interfering approach can help to adjudicate some fundamental distributive issues relative to intergenerational justice. However, a strong relation is established between liberal views of individual autonomy and non-interference, and egalitarian principles in the Rawlsian tradition.