‘Positional goods’, a term coined by Fred Hirsch, is an important concept in economics, social sciences and philosophy; however, it is used in different ways. This paper recovers Hirsch’s concept of positional goods as scarce goods that are fixed or near-fixed in supply and argues for the usefulness of this concept. Hirsch’s concept may have explanatory power beyond the concept used by most economists – that of Robert Frank. Moreover, Hirsch’s concept is more explanatorily basic and useful than the concept used by most philosophers – that of Brighouse and Swift.

Thirty-five years have passed since the killing of the South African refugee Jerry Masslo in Villa Literno in 1989 to the death of the Indian labourer Satnam Singh in Latina in 2024, marked by exploitation, violence, and abuses in the Southern Italian countryside. Only a few journalistic reports have documented this situation, and the article aims to fill this historiographical gap with a timely investigation, calling for the start of an international debate on the inhuman working conditions of foreigners in the countryside of developed countries. The article highlights some variables that have remained steady over time: the absence of public policies to regularise agricultural labour, the widespread presence of informal settlements in the countryside with risks to the safety of farm labourers, the low wage levels that violate people’s dignity, the persistent illegality in recruiting labour through ‘caporalato’ (forced labour), deaths at work due to exploitation and climate change. These are elements of critical analysis that call for an in-depth reflection on how to improve the working conditions of labourers in the rural economy today. The contribution of foreigners, as emerges from the quantitative analysis in the article, is irreplaceable for the well-being of developed societies. This is why history has an essential ethical and civic mission in highlighting the conditions of severe exploitation in which they are forced to work.

This study explores whether DNA methylation (DNAm) mediates the association between lean body mass (LBM) and cognition, as well as whether LBM mediates the association between DNAm and cognition. Based on the data of 59 monozygotic twin pairs, mediation analyses were performed using causal inference test method and mediation analyses. Average causal mediation effect (ACME), average direct effect (ADE), and total effect (TE) were calculated. Among the CpGs associated with LBM, five located within PDGFRB and RP11 genes (ACME: −0.0972−0.0463, |ACME/ADE|: 10.44%−18.30%) negatively mediated the association between LBM and cognition, while one in the PAX2 gene (ACME: 0.3510, |ACME/TE|: 11.84%) positively mediated the association. Besides, the methylation risk score (MRS) of RP11 gene (ACME: −0.0517, |ACME/ADE|: 10.64%) and MRS of all CpGs (ACME: −0.0511, |ACME/ADE|: 10.53%) negatively mediated the association of LBM with cognition. For another, LBM negatively mediated the association between the DNAm level of one CpG within UBXN6 and cognition (ACME: −0.0732, |ACME/TE|: 20.78%), while positively mediated the association between the DNAm level of four CpGs within FOXI2 and cognition (ACME: 0.2812−0.4496, |ACME/TE|: 18.15%−27.29%). It was found the DNAm in PDGFRB, RP11 and PAX2 partially mediates the association between LBM and cognition, and the association between DNAm in UBXN6 and FOXI2 with cognition is also partially mediated by LBM.

This paper revisits the relationship between tax evasion and tax rates in a heterogeneous-agent, incomplete-markets model. Extending the foundational works of Allingham and Sandmo (1972) and Yitzhaki (1974), we explore how financially constrained households use tax evasion to mitigate the adverse effects of market imperfections. We show that deterrence policies, such as audit probabilities and penalties, exacerbate the effects of borrowing constraints. Importantly, increasing income tax rates can sometimes alleviate these negative impacts when individuals evade taxes. We identify three mechanisms shaping underreporting: the direct effect, the threshold effect, and the income effect. These help explain when and why the Yitzhaki puzzle arises. Numerical results reveal a non-monotonic relationship between tax rates and underreporting, underscoring the relative strength of these effects and offering fresh insights into the Yitzhaki puzzle.

Gel’fand–Dorfman algebras (GD algebras) give a natural construction of Lie conformal algebras and are in turn characterized by this construction. In this article, we define the Gel’fand–Dorfman bialgebra (GD bialgebra) and enrich the above construction to a construction of Lie conformal bialgebras by GD bialgebras. As a special case, Novikov bialgebras yield Lie conformal bialgebras. We further introduce the notion of the Gel’fand–Dorfman Yang–Baxter equation (GDYBE), whose skew-symmetric solutions produce GD bialgebras. Moreover, the notions of $\mathcal {O}$-operators on GD algebras and pre-Gel’fand–Dorfman algebras (pre-GD algebras) are introduced to provide skew-symmetric solutions of the GDYBE. The relationships between these notions for GD algebras and the corresponding ones for Lie conformal algebras are given. In particular, there is a natural construction of Lie conformal bialgebras from pre-GD algebras. Finally, GD bialgebras are characterized by certain matched pairs and Manin triples of GD algebras.

During nematode surveys conducted to investigate the biodiversity of plant-parasitic nematodes in Mediterranean olive groves with different management strategies (organic and conventional), a nematode population of the genus Neothada was detected in southern Spain. Application of integrative taxonomical approaches clearly demonstrated that it is a new species described herein as Neothada olearum sp. nov., also representing the first report of the genus in Spain. The new species is amphimictic, characterised by a short body (563–774 μm); cuticle widely annulated (2.5–3.0 μm); total number of body annuli 214–226; 16 longitudinal ridges giving a tessellate body surface; stylet without distinct basal knobs (9.0–11.0 μm); and tail elongate-conoid, with tip bluntly rounded. The results of molecular analysis of D2-D3 28S rRNA, ITS rRNA, partial 18S rRNA, and cytochrome oxidase c subunit 1 (COI) gene sequences support for the new species status and clearly separated from N. major and other species within Neothada. Phylogenetic analyses of ribosomal and mitochondrial markers of this study suggested that Neothada is a monophyletic genus, clearly separated from Thada.

This paper studies voter turnout and selective abstention on voting days with more than one election or referendum. We extend the rational choice model to a setting with multiple concurrent votes. The model is based on a voter’s net benefit, which includes a vote’s salience and information costs. It explains how the net benefit of different concurrent votes enters a voter’s utility function and thereby affects turnout and selective abstention, the tendency to vote in one but not all votes held on the same day. We test our theoretical predictions using data on concurrent propositions in Switzerland from 1988 to 2016. Our results suggest that the proposition with the highest net benefit and the sum of the net benefits of all concurrent propositions are relevant determinants of the individual turnout decision. We also find that a proposition’s net benefit explains variation in selective abstention.

To mitigate the risk of harm to themselves or others, people with mental disorders may require compulsory admission to hospital for in-patient treatment. In England and Wales this is authorised under the Mental Health Act 1983 (MHA). Patients have the right to appeal against this involuntary detention at a hearing before the First-tier Tribunal (Health Education and Social Care Chamber) Mental Health, and psychiatrists may be called on to provide written and oral evidence to the tribunal. The purpose of this article is to help psychiatrists, particularly trainees, understand the sections of the MHA involved, the patient’s right of appeal, the role of the tribunal, their own role as a professional witness, and how to improve the quality of evidence they provide.

How do authoritarian actors navigate the liberal international order, adopting democratic facades without committing to democratic principles? And why is it so difficult for the international normative system to debunk their pretence when it comes to the use of democratic values? This paper explores this question by introducing ‘profilicity’ and ‘performativity’ as key concepts to understand how autocratic regimes build powerful profiles within a liberal system that values authenticity. Unlike conventional theories, which assume that engagement with liberal norms requires genuine commitment, profilicity reveals that strategic image-building can be just as effective. Through this lens, we see how autocracies exploit liberalism’s own ideals, using performative adaptation to secure status and reshape norms. This paper suggests that the liberal order’s emphasis on sincerity may itself be a strategic weakness, one that autocratic actors skilfully navigate in a world increasingly driven by profiles over principles.