Dynamics of value-tracking in financial markets

The effciency of a modern economy depends on value-tracking: that market prices of key assets broadly track some underlying value. This can be expected if a suffcient weight of market participants are valuation- based traders, buying and selling an asset when its price is, respectively, below and above their well-informed private valuations. Such tracking will never be perfect, and we propose a natural unit of tracking error, the 'deciblack' . We then use a simple discrete-time model to show how large tracking errors can arise if enough market participants are not valuation-based traders, regardless of how much information the valuation-based traders have. Similarly to Lux [17] and others who study subtly different models, we find a threshold above which value-tracking breaks down without any changes in the underlying value of the asset. We propose an estimator of the tracking error and establish its statistical properties. Because financial markets are increasingly dominated by non-valuation-based traders, assessing how much valuation-based investing is required for reasonable value tracking is of urgent practical interest

Scaling in Late Stage Spinodal Decomposition with Quenched Disorder

We study the late stages of spinodal decomposition in a Ginzburg-Landau mean field model with quenched disorder. Random spatial dependence in the coupling constants is introduced to model the quenched disorder. The effect of the disorder on the scaling of the structure factor and on the domain growth is investigated in both the zero temperature limit and at finite temperature. In particular, we find that at zero temperature the domain size, $R(t)$, scales with the amplitude, $A$, of the quenched disorder as $R(t) = A^{-\beta} f(t/A^{-\gamma})$ with $\beta \simeq 1.0$ and $\gamma \simeq 3.0$ in two dimensions. We show that $\beta/\gamma = \alpha$, where $\alpha$ is the Lifshitz-Slyosov exponent. At finite temperature, this simple scaling is not observed and we suggest that the scaling also depends on temperature and $A$. We discuss these results in the context of Monte Carlo and cell dynamical models for phase separation in systems with quenched disorder, and propose that in a Monte Carlo simulation the concentration of impurities, $c$, is related to $A$ by $A \sim c^{1/d}$.Comment: RevTex manuscript 5 pages and 5 figures (obtained upon request via email [email protected]

The low temperature interface between the gas and solid phases of hard spheres with a short-ranged attraction

At low temperature, spheres with a very short-ranged attraction exist as a close-packed solid coexisting with an infinitely dilute gas. We find that the ratio of the interfacial tension between these two phases to the thermal energy diverges as the range of the attraction goes to zero. The large tensions when the interparticle attractions are short-ranged may be why globular proteins only crystallise over a narrow range of conditions.Comment: 6 pages, no figures (v2 has change of notation to agree with that of Stell

Polymorphic Cis- and Trans-Regulation of Human Gene Expression

Using genetic and molecular analyses, we identified over 1,000 polymorphic regulators that regulate expression levels of human genes

Loving the mess: navigating diversity and conflict in social values for sustainability

This paper concludes a special feature of Sustainability Science that explores a broad range of social value theoretical traditions, such as religious studies, social psychology, indigenous knowledge, economics, sociology, and philosophy. We introduce a novel transdisciplinary conceptual framework that revolves around concepts of ‘lenses’ and ‘tensions’ to help navigate value diversity. First, we consider the notion of lenses: perspectives on value and valuation along diverse dimensions that describe what values focus on, how their sociality is envisioned, and what epistemic and procedural assumptions are made. We characterise fourteen of such dimensions. This provides a foundation for exploration of seven areas of tension, between: (1) the values of individuals vs collectives; (2) values as discrete and held vs embedded and constructed; (3) value as static or changeable; (4) valuation as descriptive vs normative and transformative; (5) social vs relational values; (6) different rationalities and their relation to value integration; (7) degrees of acknowledgment of the role of power in navigating value conflicts. In doing so, we embrace the ‘mess’ of diversity, yet also provide a framework to organise this mess and support and encourage active transdisciplinary collaboration. We identify key research areas where such collaborations can be harnessed for sustainability transformation. Here it is crucial to understand how certain social value lenses are privileged over others and build capacity in decision-making for understanding and drawing on multiple value, epistemic and procedural lenses.Peer reviewe

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e. a controlling message) compared to no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly-internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared to the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly-internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing: Controlled motivation was associated with more defiance and less long-term behavioral intentions to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

A global experiment on motivating social distancing during the COVID-19 pandemic

Significance Communicating in ways that motivate engagement in social distancing remains a critical global public health priority during the COVID-19 pandemic. This study tested motivational qualities of messages about social distancing (those that promoted choice and agency vs. those that were forceful and shaming) in 25,718 people in 89 countries. The autonomy-supportive message decreased feelings of defying social distancing recommendations relative to the controlling message, and the controlling message increased controlled motivation, a less effective form of motivation, relative to no message. Message type did not impact intentions to socially distance, but people’s existing motivations were related to intentions. Findings were generalizable across a geographically diverse sample and may inform public health communication strategies in this and future global health emergencies. Abstract Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

Functional traits relating arable weed communities to crop characteristics

International audienceQuestion: Which weed traits respond to the community assembly filters imposed by cropping regimes and how do they respond? Which crop characteristics (traits or aspects of field management) represent the strongest filters on weed traits? Location: France. Methods: In 561 arable fields, we measured associations between crop characteristics and (i) mean values of quantitative weed traits at each site and (ii) composition of optimally defined weed functional types, based on both qualitative and quantitative weed traits and typologies. The crop characteristics included crop height, propagule size, family and sowing date; we also used basic types (winter wheat, maize, etc.) for comparison. Results: Crop sowing date was strongly related to many weed traits, whereas crop type was not the strongest predictor of any trait. With later sowing of crops, weeds started flowering later, germinated later and had shorter flowering periods. Sowing date was also associated with the distribution of Raunkiaer life forms, while crop architecture was associated with the distribution of weed heights and a C-S-R classification. Conclusions: Cropping regimes can usefully be summarized by the crop sowing date. Phenological traits of weeds as well as classifications based on life form and C-S-R are important descriptors of weed community composition. Such findings may help predict the effects of particular crop rotations, novel crop varieties and invasive weed species