Recent publications
In this work, we extend the MPC-in-the-Head framework, used in recent efficient zero-knowledge protocols, to work over the ring \(\mathbb {Z}_{2^k}\), which is the primary operating domain for modern CPUs. The proposed schemes are compatible with any threshold linear secret sharing scheme and draw inspiration from MPC protocols adapted for ring operations. Additionally, we explore various batching methodologies, leveraging Shamir’s secret sharing schemes and Galois ring extensions, and show the applicability of our approach in RAM program verification. Finally, we analyse different options for instantiating the resulting ZK scheme over rings and compare their communication costs.
About 295,000 women died globally during and following pregnancy and childbirth in 2017. Two-thirds of these deaths occurred in Sub-Saharan Africa. By linking individual and regional data from 135 regions in 17 Sub-Saharan African countries over the period 2002–2018 this study explores how bribery affects maternal mortality in Sub-Saharan Africa. Our results show that the percentage of people who had first-hand experience in bribery is significantly and positively associated with pregnancy related deaths. We find that a 10 p.p. increase in the prevalence of bribery is associated with up to 41 [95% CI: 10–73] additional deaths for every 1,000 pregnancy-related deaths. However, the healthcare system quality appears to be an important moderator. To reduce maternal mortality, policy makers should not only increase investments in healthcare, they need also to implement measures to combat corruption.
Hierarchical models are a popular way to borrow information across groups of datapoints, which share similar, but not identical, features. When the observations are binary, the probit link function is one of the possible choices to model the probability of success within each group. It is then common to use a Gibbs sampler that alternates sampling from the full conditionals of the local and global parameters. Leveraging on recent advances in [3], we prove that the associated mixing times scale well as the number of groups grows, under warm start and random generating assumptions. The theoretical results are illustrated on simulated data.
We study the fine regularity properties of optimal potentials for the dual formulation of the Hellinger–Kantorovich problem (HK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textsf{H}\!\!\textsf{K}$$\end{document}), providing sufficient conditions for the solvability of the primal Monge formulation. We also establish new regularity properties for the solution of the Hamilton–Jacobi equation arising in the dual dynamic formulation of HK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textsf{H}\!\!\textsf{K}$$\end{document}, which are sufficiently strong to construct a characteristic transport-growth flow driving the geodesic interpolation between two arbitrary positive measures. These results are applied to study relevant geometric properties of HK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\textsf{H}\!\!\textsf{K}$$\end{document} geodesics and to derive the convex behaviour of their Lebesgue density along the transport flow. Finally, exact conditions for functionals defined on the space of measures are derived that guarantee the geodesic λ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\lambda $$\end{document}-convexity with respect to the Hellinger–Kantorovich distance. Examples of geodesically convex functionals are provided.
Empirical studies on the landscape of neural networks have shown that low-energy configurations are often found in complex connected structures, where zero-energy paths between pairs of distant solutions can be constructed. Here, we consider the spherical negative perceptron, a prototypical nonconvex neural network model framed as a continuous constraint satisfaction problem. We introduce a general analytical method for computing energy barriers in the simplex with vertex configurations sampled from the equilibrium. We find that in the overparametrized regime the solution manifold displays simple connectivity properties. There exists a large geodesically convex component that is attractive for a wide range of optimization dynamics. Inside this region we identify a subset of atypical high-margin solutions that are geodesically connected with most other solutions, giving rise to a star-shaped geometry. We analytically characterize the organization of the connected space of solutions and show numerical evidence of a transition, at larger constraint densities, where the aforementioned simple geodesic connectivity breaks down.
We review theory and research on how work events and experiences influence employee well-being, with a particular focus on the day-to-day effects of positive events and experiences. Then we discuss how employees can amplify the beneficial effects of work on well-being by savoring and reflecting upon positive events and experiences from work, and by capitalizing on them via interpersonal means, such as sharing work events and experiences with others. We integrate theory and research on savoring and interpersonal capitalization within affective events theory and the broader job demands–resources (JD-R) theory—and we explain how these approach-oriented agentic strategies that employees can easily use to derive additional psychological benefits from work experiences can extend JD-R theory. Specifically, we discuss how using these strategies can build additional resources, fulfill employees’ basic psychological needs, and make their jobs more meaningful, thereby enhancing well-being at the day-to-day level and in the long term.
Expected final online publication date for the Annual Review of Organizational Psychology and Organizational Behavior, Volume 11 is January 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Research on innovation ecosystems has identified their evolution phases but neglected their emergence, which we know little about. We offer inductive theory to explain the emergence of the nanotechnology ecosystem in Israel. Our theory suggests that ineffective bureaucracy, resource constraints, and the conflicting agendas of the government and universities create organizational bottlenecks that impede the ecosystem's emergence. Only once these actors establish related dedicated units that are immune to these deficiencies and transition to simultaneous competition and cooperation does the innovation ecosystem begin to emerge. We further reveal how enabling and governing mechanisms legitimize the innovation ecosystem, facilitate its emergence, and direct its evolution trajectory. Hence, we extend research that has centered on subsequent phases of evolution and explain how actors interact to facilitate the emergence of the ecosystem following technological discovery. Our study contributes to strategy research on interfirm coopetition by applying this concept to government and university actors, and by alluding to its multiple facets: identity, direction, administration, and resources. We also complement innovation research on the post‐formation dynamics of ecosystems by providing insights into the missing link between technological discovery and the creation of an innovation ecosystem that brings together stakeholders to commercialize that technology.
This study theorizes and empirically tests whether firms' decisions to join multi‐stakeholder initiatives, targeting climate mitigation, lead to improved environmental performance. We focus on firms' participations in the Science Based Targets initiative, a multi‐stakeholder initiative meant to support firms in setting greenhouse gas (GHG) emission reduction targets in line with the thresholds defined by the Paris Agreement in 2015. The study hypothesizes that participation reduces firm's concerns about uncertainty and encourages investments in timeous internal climate change activities. We used the coarsened exact matching methodology to create a matched sample of European and North American listed firms participating in the initiative and comparable, non‐participating firms over a 3‐year period from 2015 to 2017. The results showed that firms' participation led to lower levels of GHG emissions compared to similar non‐participating counterparts, especially when they committed to the initiative with the intention to follow the proposed indications.
We investigate trends in income inequality in the European Union (EU) from 2007 to 2019. Using EU-SILC data, we find that EU-wide inequality declined between 9% and 20%, depending on the inequality measure applied, despite rising within-country income inequality during the same time period. Applying a series of decomposition techniques, we find that between-country convergence in pre-tax/transfer incomes fully explains the declining EU-wide inequality. Changes in tax and transfer systems, in contrast, contributed to marginally higher inequality in 2019 compared to 2007. Nonetheless, the 10th percentile of the EU-wide income distribution grew six times the rate of the 90th percentile, a product of widespread earnings gains among residents of lower-income EU Member States. Re-centered influence functions and Kitigawa-Oaxaca-Blinder analyses reveal that those earnings gains are not due to specific compositional or employment changes but rather are due to rising earnings returns to employment in lower-income Member States. Despite the contribution of between-country income convergence in reducing EU-wide inequality between 2007 and 2019, however, within-country income disparities continue to explain the larger share of EU-wide inequality levels in 2019. Thus, reducing within-country economic disparities is increasingly important for achieving further reductions in EU-wide inequality moving forward.
The paper argues for a pragmatist understanding of the reasonable doubt standard in law. It builds on the idea that our dispositions to act signal the epistemic states we are in. This helps clarify the notion of a reasonable doubt and the idea of being certain beyond it.
More specifically, the paper points out three major standards of proof used in legal contexts and the rationale of their distinction. It articulates the received view according to which the reasonable doubt standard is superior to allegedly subjective standards as the French “intime conviction”; then it addresses what I call the “rampant critique” of the reasonable doubt standard, namely the view that, as the notion of a reasonable doubt is obscure and undetermined, the standard is irremediably subjective. The paper finally presents a pragmatist understanding and defense of the standard, building on the idea of beliefs as dispositions to act.
This article critically evaluates the effectiveness of the European Union's recent Directive on restructuring and insolvency law, specifically within the context of France, aimed at facilitating the restructuring of financially distressed firms within the Eurozone. Specifically, through the Kaplan–Meyer estimator and the log‐rank test, this research rigorously examines whether preventive restructurings surpass standard bankruptcy procedures in efficiency. The dataset under analysis is distinctly tailored, focusing on companies undergoing both types of restructuring procedures within the French jurisdiction. The study reveals that companies successfully undergoing a preventive restructuring procedure showcase higher survival rates, albeit coupled with weaker financial performances when compared to their counterparts undergoing the traditional bankruptcy process. This outcome challenges the prevalent assumption linking early‐stage restructuring with uniformly elevated survival rates and improved financial performance. A noteworthy concern stems from this observed trend, suggesting that the existence of discrete preventive restructuring procedures might inadvertently prolong the operational lifespan of financially inviable firms. This underscores the necessity for policymakers to meticulously craft preventive restructuring procedures, prioritizing debtor protection while proactively addressing the moral hazard predicament.
Leaders play a pivotal role in establishing ethical norms and behaviors within organizations. Across seven studies (three in the Supplementary Information), we explore how subordinates infer their leader’s moral character outside the domain of ethical conduct and document this process’s downstream consequences. Specifically, we focus on the dual-strategies theory, which posits that leaders exert influence and obtain deference via two broad orientations of behaviors and cognitions: dominance and prestige. In a field setting of employees and their managers, we find that leader dominance orientation positively relates to subordinate self-reported unethical behavior, whereas leader prestige is negatively related to the same. In a second sample of working adults, we use a time-lagged study design to show that leader dominance (prestige) positively (negatively) relates to subordinate-reported unethical behavior at work partly because of a belief that the leaders engage in more (less) unethical behaviors, which contributes to a belief that norm-violating behaviors are more (less) acceptable within teams under dominance- (prestige-) oriented leaders. Finally, across four experimental studies, we observe that participants assigned to a dominance-oriented (versus prestige-oriented) leader perceived their leader as having lower moral character and expressed a greater likelihood of engaging in unethical behavior. We also document actual unethical behavior for monetary gain. This effect was mediated by the belief that unethical behavior was normative within the team. Our results highlight the importance of moral (mis)perception by demonstrating the consequences of a leader’s hierarchical orientation on subordinate ethical perceptions and behaviors at work.
Supplemental Material: The online appendix is available at https://doi.org/10.1287/orsc.2021.15640 .
This study analyzes how healthcare organizations (HCOs)’s General Directors (GD) shaped the communication strategies toward internal and external stakeholders to keep fulfilling the organization mission during the COVID-19 crisis. Italy has been chosen as the study setting being one of the first Western countries to be heavily affected by the pandemic. Thus, a qualitative study has been designed to get an in-depth understanding of how the HCOs’ GDs, the crisis managers, defined and adopted the communication strategies both toward the internal and the external stakeholders. The findings allow to define the type of communication strategies that the crisis managers adopted towards stakeholders, more precisely a personalized communication was often used with workforce as key internal stakeholder, while a collective communication strategy was mainly adopted with external stakeholders.
This paper deals with the complex relationship between innovation and the labor market, analyzing the impact of new technological advancements on overall employment, skills, and wages. After a critical review of the extant literature and the available empirical studies, novel evidence is presented on the distribution of labor-saving automation [namely robotics and artificial intelligence (AI)], based on natural language processing of US patents. This mapping shows that both upstream high-tech providers and downstream users of new technologies—such as Boeing and Amazon—lead the underlying innovative effort.
In 2021, the federal government of the United States expanded a set of income transfers that led to strong reductions in child poverty. This research note uses microdata from more than 50 countries and U.S. data spanning more than 50 years to place the 2021 child poverty rate in historical and international perspective. We demonstrate that whether using the Supplemental Poverty Measure (SPM), relative poverty measures, or an absolute poverty measure, the U.S. child poverty rate in 2021 was at its lowest level since at least 1967. The U.S. tax and transfer system reduced the 2021 SPM child poverty rate by more than 75% relative to the pre-tax/transfer child poverty rate; this reduction was three times the mean reduction effect between 1967 and 2019. These policy changes improved the country's standing from having a relative poverty rate twice that of Germany's in 2019 to the same as Germany's in 2021. Moreover, the U.S. progressed from reducing child poverty at less than half the rate of Norway in 2019 to a rate comparable to Norway in 2021. However, the U.S. success was temporary: after the expiration of the 2021 income provisions, the child poverty rate doubled and returned to being higher than in most other high-income countries.
This paper proposes the volatility of sovereign credit default swaps (CDS) as a measurement of economic uncertainty. Sovereign CDS provide protection against losses from sovereign defaults and are traded for almost all countries by the world’s largest financial institutions. The premium for protection, the so-called CDS spread, depends on a country’s economic conditions and provides an outside view from global financial institutions. Our empirical results show that the volatility of sovereign CDS spreads contains information about economic uncertainty. For a broad panel of 16 countries, we find that sovereign CDS volatility shares directional information with popular news-based economic policy uncertainty (EPU) indices. Using Bayesian panel vector autoregressions, we find similar responses of output and unemployment to shocks in CDS volatility, equity volatility, and EPU. Our results further suggest that sovereign CDS volatility primarily reflects economic and financial uncertainty rather than political uncertainty.
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