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Wild fish use visual cues to recognize individual divers
No full textMany animal species have been shown to discriminate between individual humans in captive settings and may use a variety of cues to do so. Empirical evidence remains scarce for animals in the wild, however, particularly in aquatic contexts. For the first time, we investigated discrimination of individual humans by fish in the wild. We first trained two species of fish, saddled sea bream Oblada melanura and black sea bream Spondyliosoma cantharus, to follow a human diver to obtain a food reward. We then investigated whether they could discriminate between two human divers and follow the correct one in an operant-conditioning paradigm. We show that both species were able to quickly learn to discriminate between the two divers when they wore different diving gear. However, they showed no preference when both divers wore identical gear, suggesting that discrimination is based predominantly on visual cues from the dive gear. We discuss the implications of these results for ethical considerations and research practices.publishe
Designing citizen renewable energy projects for women : Evidence from a choice experiment in Germany
No full textCitizen renewable energy projects address the growing need for scaling up renewable energy generation. Considering the underrepresentation of women in energy transition topics, we investigate women's intention to participate in such projects, specifically which factors are most impactful for motivating women as compared to men. We employ a stated choice approach to assess the impact of a variety of variables including energy source, type of organization, minimal investment, expected annual return on investment, capital commitment period, average risk of capital loss, intensity of participation opportunity, composition of active participants and geographic expansion. The results highlight the importance of correctly setting minimal investments and risk expectations for both women and men. We find that women choose projects with higher female participation rates and are less motivated by higher expected annual return of investment than men. Implications for higher involvement of women in the energy transition are discussed.publishe
Convex monotone semigroups and their generators with respect to Γ-convergence
No full textWe study semigroups of convex monotone operators on spaces of continuous functions and their behaviour with respect to Γ-convergence. In contrast to the linear theory, the domain of the generator is, in general, not invariant under the semigroup. To overcome this issue, we consider different versions of invariant Lipschitz sets which turn out to be suitable domains for weaker notions of the generator. The so-called Γ-generator is defined as the time derivative with respect to Γ-convergence in the space of upper semicontinuous functions. Under suitable assumptions, we show that the Γ-generator uniquely characterizes the semigroup and is determined by its evaluation at smooth functions. Furthermore, we provide Chernoff approximation results for convex monotone semigroups and show that approximation schemes based on the same infinitesimal behaviour lead to the same semigroup. Our results are applied to semigroups related to stochastic optimal control problems in finite and infinite-dimensional settings as well as Wasserstein perturbations of transition semigroups.publishe
Is There a Description–Experience Gap in Choices Between a Described and an Experienced Option?
No full textDecision makers seem to evaluate risky options differently depending on the learning mode—that is, whether they learn about the options’ payoff distributions from a summary description (decisions from description) or by drawing samples from them (decisions from experience). Are there also discrepancies when people choose between a described and an experienced option? In two experiments, we compared people’s behavior in a condition with mixed learning modes (i.e., one option described, the other experienced with the sampling paradigm) to that in conditions where both options were either described or experienced. Using cumulative prospect theory’s value and probability weighting functions to characterize how observed outcome and probability information was subjectively distorted in people’s choices, we found clear differences between the pure description and pure experience conditions. In the mixed-mode condition, however, the value and probability weighting functions did not differ between the described and the experienced options, suggesting that people evaluated them based on a joint representation despite the different learning modes. Participants’ choices were not biased toward the described or the experienced option. Finally, per-option search effort for an experienced option tended to be higher in the mixed-mode condition than in the purely experience-based condition. Our findings demonstrate that how people evaluate described and experienced options depends on the learning mode of the other option in the choice set, highlighting a previously overlooked boundary condition of discrepancies between description- and experience-based choice.publishe
Spatial position relative to group members affects weight gain in meerkats, Suricata suricatta
No full textSocial animals often face a trade-off between the costs of foraging competition among group members and the benefits of protection from predators offered by group living. The spatial position of an individual in relation to the other group members during foraging can mediate the effects of this trade-off as individuals at the front or edge may have better access to food resources, but also higher predation risk than individuals near the centre of the group. Using meerkats, Suricata suricatta, as a model species, we investigated the effect of individual spatial position within a group on foraging success. We determined the spatial position of individuals in a meerkat group by fitting the animals with high-resolution GPS loggers. As a proxy of foraging success, we used meerkats' individual body weight differences between the start and the end of daily data collection over foraging periods (3 h). We found significant individual differences in meerkats’ spatial positions within the group. In addition, age-dependent differences in spatial position became obvious, with older meerkats spending less time in the centre of the group and more time in side
positions, subordinate females spending less time in the front, and subordinate males spending more time in the back. Younger meerkats who spent more time in the front of the group relative to older meerkats had decreased daily weight gain, indicating less successful foraging. We also found that the dominant females tended to spend more time towards the front of the group, but gained less weight in this position, contrary to the predicted association between front edge of the group and better access to food resources. Our results suggest that the relationship between weight gain and spatial position is highly nuanced and likely to be dependent on more than just trade-offs between foraging success and predation risk.publishe
High kinetic inductance cavity arrays for compact band engineering and topology-based disorder meters
No full textpublishe
Bioacoustic fundamental frequency estimation: a cross-species dataset and deep learning baseline
No full textThe fundamental frequency (F0) is a key parameter for characterising structures in vertebrate vocalisations, for instance defining vocal repertoires and their variations at different biological scales (e.g. population dialects, individual signatures). However, the task is too laborious to perform manually, and its automation is complex. Despite significant advancements in the fields of speech and music for automatic F0 estimation, similar progress in bioacoustics has been limited. To address this gap, we compile and publish a benchmark dataset of over 250,000 calls from 14 taxa, each paired with ground truth F0 values. These vocalisations range from infra-sounds to ultra-sounds, from high to low harmonicity, and some include non-linear phenomena. Testing different algorithms on these signals, we demonstrate the potential of neural networks for F0 estimation, even for taxa not seen in training, or when trained without labels. Also, to inform on the applicability of algorithms to analyse signals, we propose spectral measurements of F0 quality which correlate well with performance. While current performance results are not satisfying for all studied taxa, they suggest that deep learning could bring a more generic and reliable bioacoustic F0 tracker, helping the community to analyse vocalisations via their F0 contours.publishe
The reliability of replications : a study in computational reproductions
No full textThis study investigates researcher variability in computational reproduction, an activity for which it is least expected. Eighty-five independent teams attempted numerical replication of results from an original study of policy preferences and immigration. Reproduction teams were randomly grouped into a ‘transparent group’ receiving original study and code or ‘opaque group’ receiving only a method and results description and no code. The transparent group mostly verified original results (95.7% same sign and p -value cutoff), while the opaque group had less success (89.3%). Second-decimal place exact numerical reproductions were less common (76.9 and 48.1%). Qualitative investigation of the workflows revealed many causes of error, including mistakes and procedural variations. When curating mistakes, we still find that only the transparent group was reliably successful. Our findings imply a need for transparency, but also more. Institutional checks and less subjective difficulty for researchers ‘doing reproduction’ would help, implying a need for better training. We also urge increased awareness of complexity in the research process and in ‘push button’ replications.publishe
The Green Transition in the Labor Market and its Political Consequences
No full textThe green transition, designating the economic transition towards carbon neutrality, has started to and is predicted to further transform labor markets in advanced capitalist economies over the following decades. This transformation creates winners and losers in the labor market, with jobs in carbon-dependent industries particularly threatened. These distributional consequences are likely to matter for domestic politics. Yet, given the large disruptions accompanying the green transition, we know surprisingly little about the politico-economic consequences of this transition in the labor market. In this dissertation, I examine the implications of the green transition as a labor market risk for individual-level voting behavior and preferences for social and public spending policies across different advanced capitalist economies.
My theoretical argument is two-fold: First, I posit that the green transition represents a distinct source of structural change in the labor market compared to other already well-studied labor market transformations in Comparative Political Economy. This is likely to amplify its politico-economic consequences. I argue that
the green transition is characterized by a specific purpose, namely the avoidance of an existential threat posed by climate change. Relatedly, it is more driven by governmental policies than other rather market-driven sources of structural labor market change. In addition, its negative impact is concentrated in different ways: in
specific carbon-dependent industries, where low-skilled workers are overrepresented and which tend to be clustered in more rural areas. Lastly, it is much more politicized and salient in the public debate.
My second argument regarding the politico-economic consequences of the green transition is based on the dominant risk approach rooted in material self-interest to studying labor market risks in Comparative Political Economy. Unlike the majority of the existing risk-based literature, I argue that subjective perceptions of labor
market risk matter more for political reactions than objective risk in the case of the green transition for the following reasons: It is unclear whether individuals can correctly assess their objective risk and formulate policy demands accordingly. Moreover, with the politicization, salience and concentration of the burden of the green transition, subjective concerns should be more pronounced than objective risk measures would predict. Additionally, current objective risk measures are not ideal for assessing which jobs are actually at risk in an encompassing way, also because some of the labor market effects of the green transition have not occurred yet. Therefore, subjective perceptions are arguably more accurate in capturing labor market risk due to the green transition. Lastly, I depart from the dominant risk-based approach focused on material self-interest by arguing that, in the case of the green transition, non-material considerations such as social status and disappointment with specific parties also play an important role in shaping electoral reactions to labor market risks.
I test these arguments in three empirical research papers that constitute the core of this dissertation. In these papers, I use data on the closures of coal-fired power plants and coal mines, aggregate electoral records data and individual-level survey data for Germany. I also rely on data from a large novel cross-country survey
including a vignette experiment on the green transition as a labor market risk and related policy preferences. In terms of methods, I (and my co-authors) employ state-of-the-art causal inference methods, Bayesian item response theory models and multivariate regression analyses.
In Paper 1, I examine the electoral consequences of the coal phase-out in Germany after the adoption of a phase-out law in 2007. This context provides a least likely case to observe electoral backlash due to compensation for affected individuals and communities and the active involvement of labor unions in the policy-making
process. I use data on the closures of coal-fired power plants and coal mines in North-Rhine Westphalia and municipality-level aggregate election data on regional, federal and local election results between 2007 and 2022. Employing staggered Difference-in-Differences models, I show that a coal closure caused an increase in abstention rates and decreased vote shares for the Social Democratic Party in affected municipalities. While it did not cause higher unemployment rates, I provide indicative evidence, using individual-level survey data, that this asymmetric backlash stems from perceptions of economic decline and disappointment with the adoption of the phase-out policy among affected individuals, especially those close to the Social Democratic Party.
With Paper 2, which is joint work with Marius Busemeyer and Tobias Tober, we adopt a comparative perspective on the role of subjective labor market concerns due to the green transition and digitalization. We explore how individuals across six advanced capitalist economies perceive both labor market risks and whether their social policy demands differ. Analyzing both a split-sample and a vignette experiment, we find that even though individuals have more pronounced subjective labor market concerns due to the green transition compared to digitalization, they respond to both labor market challenges by favoring higher compensatory spending, such as more generous unemployment benefits, rather than social investment spending, such as more investment in higher education and life-long learning.
In Paper 3, in collaboration with Sebastian Koos, we complement this cross-country perspective on these two labor market risk perceptions by analyzing how they affect preferences on public spending on the two transitions. More specifically, we investigate the role of perceived labor market single-pressuredness and
cross-pressuredness, i.e., concern about losing one’s job due to both transformations simultaneously. Using data from the same large-scale cross-country survey as in Paper 2, our results show that subjective concern about the green transition in the labor market is associated with a preference for less relative spending on this transition. This holds in the same way for subjective perceptions of labor market risk due to digitalization. In addition, perceptions of cross-pressuredness move preferences towards a more equal spending allocation on the two transitions.
Overall, I demonstrate that subjective perceptions of labor market risk due to the green transition matter for politics, thereby situating the green transition in the existing literature on structural change in the labor market. More specifically, individuals who perceive a negative impact due to the green transition in the labor
market react with electoral backlash. They demand more compensatory social spending and generally less public spending on the green transition to maintain the status quo. These findings underscore the importance of subjective perceptions of labor market risk and economic hardship as well as non-material considerations.
These results can serve as valuable insight for policymakers and other actors, including labor unions and civil society organizations, involved in the policy-making process of green transition policies.publishe