1,720,959 research outputs found
Firm decisions under jump-diffusive dynamics
No full textWe present a model of firm investment under uncertainty and partial irreversibility in which uncertainty is represented by a jump diffusion. This allows to represent both the continuous Gaussian volatility and the discontinuous uncertainty related to information arrival, sudden changes and large shocks. The model shows how both sources of uncertainty negatively impact the optimal investment and disinvestment policies, and how the presence oflarge negative jumps can drastically affect the firm's ability to recover. Our results show that the standard Gaussian framework consistently underestimates the negative effect of uncertainty on firm investment decisions. We test these predictions on a panel dataset of UK firms: we first structurally estimate the uncertainty parameters using multinomial maximum likelihood and differential evolution techniques and subsequently study their impact on firm investment rates, validating our model predictions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Coronagraben in Switzerland: Culture and social distancing in times of COVID-19
No full textSocial distancing measures help contain the spread of COVID-19 but the actual compliance has varied substantially across space and time. We ask whether cultural differences underlie this heterogeneity using mobility data across Switzerland between February and December 2020. We find that German-speaking cantons decreased their mobility for non essential activities significantly less than the French-speaking cantons. However, we find no such significant differences for the bilingual cantons. Contrary to the evidence in the literature, we find that within the Swiss context, high trusting areas exhibited a lower decline in mobility. Additionally, cantons supporting a limited role of the state in matters of welfare also displayed a lower mobility reduction
Quickest Detection of Ecological Regimes for Natural Resource Management
Full text linkWe study the stochastic dynamics of natural resources under the threat of
ecological regime shifts. We establish a Pareto optimal framework of regime
shift detection under uncertainty that minimizes the delay with which economic
agents become aware of the shift. We integrate ecosystem surveillance in the
formation of optimal resource extraction policies. We fully solve the case of a
profit-maximizing monopolist, study its response to regime shift detection and
show the generality of our framework by extending our results to other decision
makers and functional forms.We apply our framework to the case of the
Cantareira water reservoir in S\~ao Paulo, Brazil, and study the events that
led to its depletion and the consequent water supply crisis
Channel new investment to the North, Midlands and Wales, not the South East
No full textNew research reveals that the pandemic has hit the UK’s poorest regions hardest. Neha Deopa and Piergiuseppe Fortunato (UNCTAD) argue that post-COVID investment needs to be channelled to the North, Midlands and Wales
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Social distancing why has compliance been so different across Europe?
No full textA common response to the Covid-19 pandemic across Europe has been for states to promote social distancing. Yet the level of compliance from citizens has varied substantially between countries. Drawing on data from Switzerland, Neha Deopa and Piergiuseppe Fortunato provide an illustration of the impact cultural attitudes and behavioural norms can have on compliance with social distancing measures
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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