arXiv subjects

Giorgio Laguzzi

Publications and source records attributed to Giorgio Laguzzi.

At least 19 recordsLinked to original sources

arXiv2026

On the construction and representation of social welfare orders satisfying consequentialist equity axioms

In this paper we examine the constructive nature of social welfare orders on infinite utility streams $X=Y^{\mathbb{N}}$ satisfying Strong Equity, Hammond Equity, or the Pigou--Dalton transfer principle. The constructive social welfare orders are described using lexicographic preference relations. Social welfare orders satisfying Strong Equity, Hammond Equity, or the Pigou--Dalton transfer principle admit explicit descriptions when $Y(<)$ is well-ordered. We describe restrictions on the domain $Y$ under which the existence of social welfare orders satisfying the aforementioned equity axioms entails the existence of a non-Ramsey collection. For this, we rely on the existence of a non-Ramsey collection, which is treated here as a nonconstructive object.

econ.TH↗

arXiv2023

Decision-making under risk: when is utility maximization equivalent to risk minimization?

Motivated by the analysis of a general optimal portfolio selection problem, which encompasses as special cases an optimal consumption and an optimal debt-arrangement problem, we are concerned with the questions of how a personality trait like risk-perception can be formalized and whether the two objectives of utility-maximization and risk-minimization can be both achieved simultaneously. We address these questions by developing an axiomatic foundation of preferences for which utility-maximization is equivalent to minimizing a utility-based shortfall risk measure. Our axiomatization hinges on a novel axiom in decision theory, namely the risk-perception axiom.

econ.TH↗

arXiv2022

How rare are the properties of binary relations?

Knoblauch (2014) and Knoblauch (2015) investigate the relative size of the collection of binary relations with desirable features as compared to the set of all binary relations using symmetric difference metric (Cantor) topology and Hausdorff metric topology. We consider Ellentuck and doughnut topologies to further this line of investigation. We report the differences among the size of the useful binary relations in Cantor, Ellentuck and doughnut topologies. It turns out that the doughnut topology admits binary relations with more general properties in contrast to the other two. We further prove that among the induced Cantor and Ellentuck topologies, the latter captures the relative size of partial orders among the collection of all quasi-orders. Finally we show that the class of ethical binary relations is small in Ellentuck (and therefore in Cantor) topology but is not small in doughnut topology. In essence, the Ellentuck topology fares better compared to Cantor topology in capturing the relative size of collections of binary relations.

econ.TH↗

arXiv2021

Mathias and Silver forcing parametrized by density

We define and investigate versions of Silver and Mathias forcing with respect to lower and upper density. We focus on properness, Axiom A, chain conditions, preservation of cardinals and adding Cohen reals. We find rough forcings that collapse 2^ωto ω, while others are surprisingly gentle. We also study connections between regularity properties induced by these parametrized forcing notions and the Baire property.

math.LO↗

arXiv2021

Extended Gini Index

We propose an extended version of Gini index defined on the set of infinite utility streams, $X=Y^\mathbb{N}$ where $Y\subset \mathbb{R}$. For $Y$ containing at most finitely many elements, the index satisfies the generalized Pigou-Dalton transfer principles in addition to the anonymity axiom.

econ.TH↗

arXiv2021

Equitable preference relations on infinite utility streams

We propose generalized versions of strong equity and Pigou-Dalton transfer principle. We study the existence and the real valued representation of social welfare relations satisfying these two generalized equity principles. Our results characterize the restrictions on one period utility domains for the equitable social welfare relation (i) to exist; and (ii) to admit real-valued representations.

econ.TH↗

arXiv2021

On social welfare orders satisfying anonymity and asymptotic density-one Pareto

We study the nature (i.e., constructive as opposed to non-constructive) of social welfare orders on infinite utility streams, and their representability by means of real-valued functions. We assume finite anonymity and introduce a new efficiency concept we refer to as asymptotic density-one Pareto. We characterize the existence of representable and constructive social welfare orders (satisfying the above properties) in terms of easily verifiable conditions on the feasible set of one-period utilities.

econ.TH↗

arXiv2020

Paretian social welfare relations and Baire property

We study the topological and set-theoretical nature of Paretian social welfare relations in a setting with infinite time horizon. Specifically, we answer questions posed in \citet{mathias2020} about the interplay between total welfare relations satisfying Pareto and anonymity principles with subsets of real numbers not satisfying the Baire property.

math.LO↗

arXiv2020

Social welfare relations and irregular sets

Total social welfare relations satisfying Pareto and equity principles on infinite utility streams has revealed a non-constructive nature. In this paper we study more deeply the needed fragment of AC. In particular, we show that such relations need a strictly larger fragment of AC than non-Lebesgue and non-Ramsey sets. We also prove a connection with the Baire property, answering Problem 11.14 posed in "Flutters and chameleon", by Mathias et al.

math.LO↗

arXiv2020

On the Representation and Construction of Equitable Social Welfare Orders

This paper examines the representation and explicit description of social welfare orders on infinite utility streams. It is assumed that the social welfare orders under investigation satisfy upper asymptotic Pareto and anonymity axioms. We prove that there exists no real-valued representation of such social welfare orders. In addition, we establish that the existence of a social welfare order satisfying the anonymity and upper asymptotic Pareto axioms implies the existence of a non-Ramsey set, which is a non-constructive object. Thus, we conclude that the social welfare orders under study do not admit explicit description.

math.LO↗

arXiv2020

Laver Trees in the Generalized Baire Space

We prove that any suitable generalization of Laver forcing to the space $ κ^κ$, for uncountable regular $κ$, necessarily adds a Cohen $κ$-real. We also study a dichotomy and an ideal naturally related to generalized Laver forcing. Using this dichotomy, we prove the following stronger result: if $ κ^{<κ}=κ$, then every $<κ$-distributive tree forcing on $κ^κ$ adding a dominating $κ$-real which is the image of the generic under a continuous function in the ground model, adds a Cohen $κ$-real. This is a contribution to the study of generalized Baire spaces and answers a question from arXiv:1611.08140

math.LO↗

arXiv2020

Some considerations on Amoeba forcing notions

In this paper we analyse some notions of amoeba for tree forcings. In particular we introduce an amoeba-Silver and prove that it satisfies quasi pure decision but not pure decision. Further we define an amoeba-Sacks and prove that it satisfies the Laver property. We also show some application to regularity properties. We finally present a generalized version of amoeba and discuss some interesting associated questions.

math.LO↗

arXiv2020

Uncountable trees and Cohen $κ$-reals

We investigate some versions of amoeba for tree-forcings in the generalized Cantor and Baire spaces. This answers [10, Question 3.20] and generalizes a line of research that in the standard case has been studied in [11], [13], and [7]. Moreover, we also answer questions posed in [3] by Friedman, Khomskii, and Kulikov, about the relationships between regularity properties at uncountable cardinals. We show $Σ_1^1$-counterexamples to some regularity properties related to trees without club splitting. In particular we prove a strong relationship between the Ramsey and the Baire properties, in slight contrast with the standard case.

math.LO↗

arXiv2020

Generalized Silver and Miller measurability

We present some results about the burgeoning research area concerning set theory of the kappa-reals. We focus on some notions of measurability coming from generalizations of Silver and Miller trees. We present analogies and mostly differences from the classical setting.

math.LO↗

arXiv2020

On the sepration of regularity properties of the reals

We present a model where ω_1 is inaccessible by reals, Silver measurability holds for all sets but Miller and Lebesgue measurability fail for some sets. This contributes to a line of research started by Shelah in the 1980s and more recently continued by Schrittesser and Friedman, regarding the separation of different notions of regularity properties of the real line.

math.LO↗

arXiv2020

A null ideal for inaccessibles

In this paper we introduce a tree-like forcing notion extending some properties of the random forcing in the context of the generalised Cantor space and study its associated ideal of null sets and notion of measurability. This issue was also addressed by Shelah ([11, Problem 0.5]) and concerns the definition of a forcing which is $κ^kappa$-bounding, $< κ$-closed and $κ^+$-cc, for $κ$ inaccessible.

math.LO↗

arXiv2020

On splitting trees

We investigate two variants of splitting tree forcing, their ideals and regularity properties. We prove connections with other well-known notions, such as Lebesgue measurablility, Baire- and Doughnut-property and the Marczewski field. Moreover, we prove that any \emph{absolute} amoeba forcing for splitting trees necessarily adds a dominating real, providing more support to Spinas' and Hein's conjecture that $\add(\ideal{I}_\spl) \leq \mathfrak{b}$.

math.LO↗

arXiv2020

More on trees and Cohen reals

In this paper we analyse some questions concerning trees on $κ$, both for the countable and the uncountable case, and the connections with Cohen reals. In particular, we provide a proof for one of the implications left open in \cite[Question 5.2]{FKK16} about the diagram for regularity properties.

math.LO↗