EDHEC Business School

Executive ownership is a mechanism that addresses agency problems by aligning the financial goals of management with those of shareholders. We explore whether executives’ financial objectives are also aligned with the goals of stakeholders other than shareholders. We show that executive financial goals, measured as equity ownership and insider trading intensity, was negatively associated with US firms’ environmental and social performance in the period 2002–2019. A quasi-natural experiment suggests that such inverse relationship was causal. Therefore, our results support the existence of new agency issues for firms aiming to maximize stakeholder value on the environmental and social dimensions. Our finding reinforces the call for novel mechanisms to incentivize managerial efforts towards sustainability goals.

Drawing on a qualitative study of the French textile industry, this paper examines how Circular Economy (CE) policies impact on business model innovation and the geography, organization, and environmental upgrading of global value chains (GVCs). Our findings show that while policies which promote practices such as eco-design, reuse, and recycling have stimulated change, their impact varies significantly by firm type. Multinational lead firms have mostly reacted to policy incentives by integrating minor circular adaptations into pre-existing linear, volume-driven business models, resulting in little change to the organization or geography of their GVCs. Born-circular firms, by contrast, have developed innovative value propositions that embed circularity at their core, seeking to reorganize GVCs both geographically and organizationally, notably by integrating novel actors and creating inter-sectoral linkages. However, these firms faced significant commercial and technical constraints and remained limited in scale and influence. Overall, although these adaptations have led to the integration of new intermediary actors across the value chains studied, they have generally failed to trigger systemic change or geographic shifts. While broader EU-level policies have the potential to drive more far-reaching GVC restructuring and environmental upgrading, the challenges identified here will persist, hampering progress and making sustainability outcomes uncertain.

Mielnik's cannonball argument uses the Zeno effect to argue that projective measurements for time of arrival are impossible. If one repeatedly measures the position of a particle (or a cannonball!) that has yet to arrive at a detector, the Zeno effect will repeatedly collapse its wave function away from it: the particle never arrives. Here we introduce quantum stroboscopic measurements where we accumulate statistics of projective position measurements, performed on different copies of the system at different times, to obtain a time-of-arrival distribution. We show that, under appropriate limits, this gives the same statistics as time measurements of conventional "always on" particle detectors that bypass Mielnik's argument using nonprojective, weak continuous measurements. In addition to time of arrival, quantum stroboscopy can describe distributions of general time measurements. It can also be adapted to obtain the conditional probability distribution of arrival times, given that the particle was not previously detected at the detector.

Line planning in public transport is the strategic problem of selecting lines and their operating frequencies. This problem is important as it defines the passenger service, based on available connections and expected travel times, and drives operational cost in terms of the number of vehicles required. This paper presents a line planning model that minimizes the weighted sum of passenger travel time, including in-vehicle time and frequency-dependent waiting and transfer times, and operating costs for the public transport agency. Unlike traditional approaches that assume demand to be fixed, our approach requires a minimum service level for demand to be captured, ensuring that services are provided only when they are attractive to users and cost-efficient to operate. The introduced capacity constraints ensure sufficient capacity on the lines and help guide the trade-off between expected demand on selected lines and their frequencies. The resulting mixed-integer program presents a challenging combinatorial problem as the number of passenger paths grows rapidly in relation to the number of lines and frequencies considered. To address this, we propose an iterative exact algorithm that utilizes a reduced problem representation and dynamically expands it with additional frequencies and paths. Evaluated on four networks with varying complexity and cost trade-offs, our method achieves significant speed-ups and tighter bounds compared to solving the complete model directly by CPLEX, particularly when operator and passenger costs are more evenly balanced in the objective. Furthermore, we demonstrate how accounting for lost demand leads to more efficient resource use from an overall perspective.

We propose a reformulation of quantum mechanics as a theory of unresolved uncertainty. The framework is formulated in the language of complex-valued measure theory, regarded as a pre-probabilistic counterpart of ordinary probability theory. In this formulation, additivity, conditioning, independence, mixtures, transition kernels, and temporal divisibility retain natural linear forms at the potentiality level, while non-classical probability-level features such as interference arise from the nonlinear Born map. Measurement is described as Bayesian-type conditioning of potentialities on actualized information, and non-selective measurement as the replacement of coherent potentiality by statistical mixtures of conditional branches. Mixed states, decoherence, composite systems, entanglement, and Bell-type correlations are also given a unified potentiality-level interpretation. The resulting formulation is empirically equivalent to standard quantum mechanics, but it makes explicit a pre-probabilistic description of physical reality that is usually implicit in the Hilbert-space formalism.