We characterize a family of r-extended generalized Lorenz dominance quasi-orderings and a family of r-Gini welfare orderings, on the basis of two allegedly “incompatible” axioms for heterogeneous welfare comparisons (Ebert, 1997, Ebert and Moyes, 2003, Shorrocks, 1995), but at the cost of either completeness or separability. JEL classification: D31, D63, I31.

∗Institute of Mathematics; and Center for Rationality and Interactive Decision Theory; The Hebrew University of Jerusalem; Givat Ram; Jerusalem 91904; Israel. E-mail: [email protected] This research was in part supported by The Israel Science Foundation grant 382/98. J.E.L. Classification numbers. D70, D71, D63, C71

Do the Reciprocal Trust Less? We study the intrapersonal relationship between trust and reciprocity in a laboratory experiment. Reciprocal subjects trust significantly more than selfish ones. This finding raises questions about theories of social preferences which predict that “fairer” players should trust less. JEL Classification: C91, D63

This paper studies envy-free allocations for economies with indivisible objects, quasilinear utility functions, and an amount of money. We give a polynomially bounded algorithm for finding envy-free allocations. Connectedness of envy-graphs, which are used in the algorithm, characterizes the extreme points of the polytopes of sidepayments corresponding with envy-free allocations. Classification...

We show how to minimize the probability of misclassifying individuals as being poor or not poor when data on some of their relevant attributes are missing, but an estimate of the population distribution of attributes is available. JEL Classification Codes: D63, I32

We examine the association of income variability both within and across generations based on a heterogeneous growth model of permanent and transitory income in Sweden. Non-parametric regressions reveal that income variability is strongly associated with long-run levels of income, especially for lowand highincome earners, and that it is also strongly associated across generations. JEL Classifica...

In this paper we study the mechanics of “leading by example” in teams. Leadership is beneficial for the entire team when agents are conformists, i.e., dislike effort differentials. We also show how leadership can arise endogenously and discuss what type of leader benefits a team most. JEL codes: C72; D23; D63; J31; L23.

We solve the nonlinear income tax program for rank-dependent social welfare functions, expressing trade-off between size and inequality using Gini related families of positional indices. Absent bunching, ranks in actual optimal allocations are invariant. Exploiting this feature, we provide new, simple, intuitive formulas both quasilinear additive cases new comparative static results. Our approa...

We analyze the implications of several principles related to the concept of equal (and prioritarian) entitlement to continued life. These principles, when modeled as axioms for the evaluation of health distributions, and combined with some other structural axioms, provide several characterization results of focal population health evaluation functions. JEL numbers: D63, I10.

We study minimum cost spanning tree problems and de…ne a cost sharing rule that satis…es many more properties than other rules in the literature. Furthermore, we provide an axiomatic characterization based on monotonicity properties. Keywords: Spanning tree. Cost allocation. Monotonicity. JEL Classi…cation Numbers: C71, D63, D7.