Categoria: wp2003

Some Counterexamples in Positive Dependence

Taizhong Hu, Alfred M¸ller, and Marco Scarsini: December 2002, revised March 2003 and June 2003

Abstract: We provide some counterexamples showing that some concepts of positive dependence are strictly stronger than others. In particular we will settle two questions posed by Pemantle (2000) and Pellerey (2002) concerning respectively association versus weak association, weak association versus supermodular dependence, and supermodular dependence versus positive orthant dependence

Positive value of information in games

Bruno Bassan, Olivier Gossner, Marco Scarsini, and Shmuel Zamir

Abstract: We exhibit a general class of interactive decision situations in which all the agents benefit from more information. This class includes as a special case the classical comparison of statistical experiments `a la Blackwell. More specifically, we consider pairs consisting of a game with incomplete information G and an information structure S such that the extended game Γ(G, S) has a unique Pareto payoff profile u.

We prove that u is a Nash payoff profile of Γ(G, S), and that for any information structure T that is coarser than S, all Nash payoff profiles of Γ(G, T ) are dominated by u. We then prove that our condition is also necessary in the following sense: Given any convex compact polyhedron of payoff profiles, whose Pareto frontier is not a singleton, there exists an extended game Γ(G, S) with that polyhedron as the convex hull of feasible payoffs, an information structure T coarser than S and a player i who strictly prefers a Nash equilibrium in Γ(G, T ) to any Nash equilibrium in Γ(G, S).

Property rights systems and the rule of law

Ronald A. Cass Abstract: Property rights – rights to control, use, or transfer things (broadly conceived) – though not readily distinguished from other rights, comprise a category of rights that both strongly benefit from clear and well-designed legal rules and often are subject to “chiseling” from failures to follow legal rules or from ex post alterations of the rules. Governance systems that limit official discretion to impair property rights, that have institutions and rules that provide clear definition to property rights and that provide predictable and consistent applications of those rights, will accord with the rule of law and generally will also advance social welfare.

Some systems will depart quite evidently from this pattern, to the detriment of those societies, allowing too ready changes in law at the discretion of too few officials, too unconstrained by law, as the example of Zimbabwe illustrates. But differences between the good and the bad will not be drawn along simple, discrete lines, a point made by comparing the Zimbabwe example with the United States.

The systems most consistent with the rule of law will not be able effectively to bar all changes in the law or to eliminate official discretion. Instead, those systems will limit the avenues for change and the ambit of discretion in ways that make property more secure and impositions on it more predictable without reference to the identity of the individual official enforcing the law or the individual property owners subject to it.

La questione del monopolio tra Stato e mercato: un’indagine su Bruno Leoni

Carlo Lottieri
Università di Siena e Icer di Torino
Aprile 2003

Abstract: Il paper prende in esame i principali scritti di Bruno Leoni sul monopolio e sullo Stato, con l’obiettivo di evidenziare come le sue riflessioni sul rapporto tra monopolio ed economia di mercato siano del tutto convergenti con le sue analisi politologiche sul carattere coercitivo dell’apparato statale.