We analyze the results from three different risk attitude elicitation methods. First, the broadly used test by Holt and Laury, HL, second, the lottery-panel task by Sabater-Grande and Georgantzis, SG, and third, responses to a survey question on self-assessment of general attitude towards risk. The first and the second task are implemented with real monetary incentives, while the third concerns all domains in life in general. Like in previous studies, the correlation of decisions across tasks is low and usually statistically (...) non-significant. However, when we consider only subjects whose behavior across the panels of the SG task is compatible with constant relative risk aversion, the correlation between HL and self-assessed risk attitude becomes significant. Furthermore, the correlation between HL and SG also increases for CRRA-compatible subjects, although it remains statistically non-significant. (shrink)

In this paper, we study overconfidence and goal-setting in academic performance, with and without monetary incentives. Students enrolled in a microeconomics course were offered the possibility of setting their own target grade before taking part in the final exam. They were also asked to guess their grade immediately after they had taken the exam (“post-diction”). In general, students overestimated their performance, both at the goal-setting and at the post-diction stages. Controlling for several sources of this bias (cognitive abilities, academic record (...) and self-reported academic confidence), we find that the use of monetary rewards mitigates the overestimation of potential achievements and eliminates overestimation of actual achievements through the improvement of actual performance. Our results suggest that monetary incentives do not cause subjects to put more effort into correct guesses but make them put more effort into academic performance. Using students’ academic records to measure overall skill, we find a strong Dunning–Kruger bias which is intensified in the presence of monetary rewards. (shrink)

In this article, we illustrate experimentally an important consequence of the stochastic component in choice behaviour which has not been acknowledged so far. Namely, its potential to produce ‘regression to the mean’ (RTM) effects. We employ a novel approach to individual choice under risk, based on repeated multiple-lottery choices (i.e. choices among many lotteries), to show how the high degree of stochastic variability present in individual decisions can distort crucially certain results through RTM effects. We demonstrate the point in the (...) context of a social comparison experiment. (shrink)

This paper reports results from a longitudinal study on the impact of the lockdown on daily self-reported life satisfaction levels during the first wave of the COVID-19 pandemic in Spain. A stable panel (N= 1,131) of adult subjects were surveyed during 84 consecutive days (March 29–June 20, 2020). They were asked to report daily life satisfaction and health state levels. Interestingly, daily life satisfaction increased during the lockdown. At the beginning of the experiment, subjects were asked to guess the end-week (...) of the lockdown, against a possible monetary reward for accurate forecasts. Subjects predicting a longer lockdown period reported a higher average level of daily life satisfaction. Females reported on average lower levels of daily life satisfaction, but exhibited a stronger tendency to report higher levels of life satisfaction, the longer their lockdown forecast. Individual heterogeneity in life satisfaction levels can be partly attributed to personality traits, with neuroticism having a negative effect, while extraversion and agreeableness having a positive effect on daily life satisfaction. (shrink)

It is well known that classical propositional logic can be interpreted in intuitionistic propositional logic. In particular Glivenko's theorem states that a formula is provable in the former iff its double negation is provable in the latter. We extend Glivenko's theorem and show that for every involutive substructural logic there exists a minimum substructural logic that contains the first via a double negation interpretation. Our presentation is algebraic and is formulated in the context of residuated lattices. In the last part (...) of the paper, we also discuss some extended forms of the Kolmogorov translation and we compare it to the Glivenko translation. (shrink)

This is also where we begin investigating lattices of logics and varieties, rather than particular examples.

Two constructions for adding an involution operator to residuated ordered monoids are investigated. One preserves integrality and the mingle axiom x 2x but fails to preserve the contraction property xx 2. The other has the opposite preservation properties. Both constructions preserve commutativity as well as existent nonempty meets and joins and self-dual order properties. Used in conjunction with either construction, a result of R.T. Brady can be seen to show that the equational theory of commutative distributive residuated lattices (without involution) (...) is decidable, settling a question implicitly posed by P. Jipsen and C. Tsinakis. The corresponding logical result is the (theorem-) decidability of the negation-free axioms and rules of the logic RW, formulated with fusion and the Ackermann constant t. This completes a result of S. Giambrone whose proof relied on the absence of t. (shrink)

All known structural extensions of the substructural logic $\textbf{FL}_{\textbf{e}}$, the Full Lambek calculus with exchange/commutativity (corresponding to subvarieties of commutative residuated lattices axiomatized by $\{\vee, \cdot, 1\}$ -equations), have decidable theoremhood; in particular all the ones defined by knotted axioms enjoy strong decidability properties (such as the finite embeddability property). We provide infinitely many such extensions that have undecidable theoremhood, by encoding machines with undecidable halting problem. An even bigger class of extensions is shown to have undecidable deducibility problem (the (...) corresponding varieties of residuated lattices have undecidable word problem); actually with very few exceptions, such as the knotted axioms and the other prespinal axioms, we prove that undecidability is ubiquitous. Known undecidability results for non-commutative extensions use an encoding that fails in the presence of commutativity, so and-branching counter machines are employed. Even these machines provide encodings that fail to capture proper extensions of commutativity, therefore we introduce a new variant that works on an exponential scale. The correctness of the encoding is established by employing the theory of residuated frames. (shrink)

Substructural logics have received a lot of attention in recent years from the communities of both logic and algebra. We discuss the algebraization of substructural logics over the full Lambek calculus and their connections to residuated lattices, and establish a weak form of the deduction theorem that is known as parametrized local deduction theorem. Finally, we study certain interpolation properties and explain how they imply the amalgamation property for certain varieties of residuated lattices.

Equivalences and translations between consequence relations abound in logic. The notion of equivalence can be defined syntactically, in terms of translations of formulas, and order-theoretically, in terms of the associated lattices of theories. W. Blok and D. Pigozzi proved in [4] that the two definitions coincide in the case of an algebraizable sentential deductive system. A refined treatment of this equivalence was provided by W. Blok and B. Jónsson in [3]. Other authors have extended this result to the cases of (...) k-deductive systems and of consequence relations on associative, commutative, multiple conclusion sequents. Our main result subsumes all existing results in the literature and reveals their common character. The proofs are of order-theoretic and categorical nature. (shrink)

The Bioethics Committee of the Church of Greece, headed by Metropolitan Nikolaos of Mesogaia and Lavreotiki, was founded a few years ago, bringing together clergy, medical and legal experts. In his address, Metropolitan Nikolaos explains the concerns and the conditions that led to its foundation and he outlines some of the activities and the principles of the Committee. This address, a somewhat broad-brush presentation of the state of bioethics in Greece, is offered as a proposal as to how (...) the Church can work within a secular state, and how it can attempt to raise awareness about the spiritual aspect of bioethical concerns. Overall, the Bioethics Committee tries to promote public dialogue about sensitive bioethical issues, and to make sure that the spiritual perspective is duly informed by medical science. In addition, the Committee tries to make sure that the spiritual perspective is considered by the state in the face of existing or emerging law that touches on bioethical concerns. (shrink)

We develop a general algebraic and proof-theoretic study of substructural logics that may lack associativity, along with other structural rules. Our study extends existing work on substructural logics over the full Lambek Calculus [34], Galatos and Ono [18], Galatos et al. [17]). We present a Gentzen-style sequent system that lacks the structural rules of contraction, weakening, exchange and associativity, and can be considered a non-associative formulation of . Moreover, we introduce an equivalent Hilbert-style system and show that the logic associated (...) with and is algebraizable, with the variety of residuated lattice-ordered groupoids with unit serving as its equivalent algebraic semantics. Overcoming technical complications arising from the lack of associativity, we introduce a generalized version of a logical matrix and apply the method of quasicompletions to obtain an algebra and a quasiembedding from the matrix to the algebra. By applying the general result to specific cases, we obtain important logical and algebraic properties, including the cut elimination of and various extensions, the strong separation of , and the finite generation of the variety of residuated lattice-ordered groupoids with unit. (shrink)

Given a positive universal formula in the language of residuated lattices, we construct a recursive basis of equations for a variety, such that a subdirectly irreducible residuated lattice is in the variety exactly when it satisfies the positive universal formula. We use this correspondence to prove, among other things, that the join of two finitely based varieties of commutative residuated lattices is also finitely based. This implies that the intersection of two finitely axiomatized substructural logics over FL + is also (...) finitely axiomatized. Finally, we give examples of cases where the join of two varieties is their Cartesian product. (shrink)

The aim of this volume is to explore new approaches to the problem of the constitution of the various aspects of sociality and to confront these with received ideas. Many of the contributions are devoted to a rather holistic and antireductionist conception of social objects, groups, joint actions, and collective knowledge. The topics that are dealt with are: (a) the question of the ontological status of social objects and their relation to physical objects; (b) collective agency; and (c) the question (...) whether there can be shared knowledge and shared beliefs, a rather new topic in the discussion of the social aspects of personal life. (shrink)

The purpose of this paper is first to show that if X is any locally compact but not compact perfect Polish space and stands for the one-point compactification of X, while E X is the equivalence relation which is defined on the Polish group C(X,R +*) by where f, g are in C(X,R +*), then E X is induced by a turbulent Polish group action. Second we show that given any if we identify the n-dimensional unit sphere S n with (...) the one-point compactification of R n via the stereographic projection, while E n , r is the equivalence relation which is defined on the Polish group C r (R n ,R +*) by where f, g are in C r (R n ,R +*), then E n , r is also induced by a turbulent Polish group action. (shrink)

Με αφορμή ένα γεωμετρικό αμφορέα του επιγάστριου αττικο-κυκλαδικού τύπου από το νεκροταφείο της Ελεύθερνας, διακοσμημένο με τρεις μετόπες ομόκεντρων κύκλων στη ζώνη της κοιλιάς, συζητούνται τα προβλήματα τυπολογίας και προέλευσης αυτής της χαρακτηριστικής κατηγορίας αγγείων στο φως της νεότερης έρευνας. Η τεχνοτροπία όλων των αμφορέων αυτού του τύπου, δηλ. με δύο ή με τρεις μετόπες ομοκέντρων κύκλων, ακολουθεί πάντοτε τον αττικό ρυθμό, αλλά ενώ η αττική καταγωγή των διμετο- πικών αμφορέων του τύπου ουδέποτε αμφισβητήθηκε, η καταγωγή των τριμετοπικών αμφορέων, που (...) παρουσιάζουν ευρύτατη διάδοση στο Αιγαίο και κυρίως στις Κυκλάδες, άλλοτε αποδίδεται στην Αττική και άλλοτε στις Κυκλάδες. Στη μελέτη αυτή επιχειρείται ένας επαναπροσδιορισμός της τυπολογίας του επιγάστριου ομοκεντρικού αμφορέα και συζητείται διεξοδικά η κατηγορία των αμφορέων με τρεις μετόπες. (shrink)

Interest in corporate social responsibility (CSR) is gaining momentum in academic and managerial circles. However, prior work in the area has paid little attention to how CSR initiatives should be implemented inside the organization. Against this backdrop, this study examines the impact of CSR initiatives on an important stakeholder group—employees. We build and test a comprehensive multilevel framework that focuses on whether employees derive job satisfaction from CSR programs. The proposed model predicts that a manager’s charismatic leadership influences employees’ interpretations (...) about the motives underlying their companies’ engagement in CSR initiatives (intrinsic and extrinsic CSR-induced attributions) which, in turn, influence employee job satisfaction. Hierarchical linear modeling of data from 47 organizational units comprising 438 employees from three world-leading manufacturing organizations shows that when employees think that their manager possesses charismatic leadership qualities, they tend to attribute the organization’s motives for engaging in CSR activities to intrinsic values, which, in turn, are positively associated with job satisfaction. Also, the extent to which managers are perceived as charismatic leaders relates positively to job satisfaction. Interestingly, CSR-induced extrinsic attributions are neither explained by charismatic leadership nor do they predict job satisfaction. Implications for both theory and practice are discussed. (shrink)

If X is a locally compact Polish space, then LSC denotes the compact Polish space of lower semi-continuous real-valued functions on X equipped with the topology of epi-convergence.Our purpose in this article is to prove the following: if –∞ < α < β < ∞ and –∞ < a < b < ∞, while r ∈ ℕ \ {0}, then the set CV of all f ∈ LSC for which there is u ∈ Cr such that for any v ∈ (...) Cr we have that ∫αβf , v ′)dx ≥ ∫αβf , v )dx is not Borel. (shrink)

Picturesque Galaxidi, with its good harbor (eulimenos politeia) and rich nautical tradition, was constructed on the site of ancient Chaleion. The continuous habitation of the site as well as the fact that ancient stone blocks were used to build the modern harbor facilities have contributed to the extensive destruction of the ancient structures, and in particular of the fortifications. These last, which were likely founded in the late 4th century BC, are preserved in fragments among the modern city. This paper (...) gathers the results of previous and more recent studies, mainly of a rescue nature. Its aim is to graphically reconstruct, with the greatest possible degree of accuracy, the course of the walls, and to understand the defensive function of the fortification in the context of contemporary siege operations. (shrink)