1,721,939 research outputs found
Prediction of planning craft motions in waves using 2D CFD coupled with strip theory
No full textEThOS - Electronic Theses Online ServiceGBUnited Kingdo
Sovereign contingent liabilities: a perspective on default and debt crises
Full text linkChapters 2-3: A global games approach to sovereign debt crises The first chapters present a model that investigates the risks involved when a fiscal authority attempts to roll-over a stock of debt and there is the potential for coordination failure by investors. A continuum of investors, after receiving signals about the authority's willingness to repay, decides whether to roll-over the stock of debt. If an insufficient proportion of investors participates, the authority defaults. With one fiscal authority, private information results in a deterministic outcome. When a public signal is available, the model behaves in a similar manner to a sunspot model. In line with much of the global games literature, improving public information has an ambiguous effect on welfare. Finally, the model is extended to include a second fiscal authority, which captures a similar sunspot result and illustrates the potential for externalities in fiscal policy. Lower debt in the less indebted authority can push a more indebted authority into crisis. Lower debt makes the healthier authority relatively more attractive, which causes the investors to treat the heavily indebted authority more conservatively. In certain circumstances, this is sufficient to cause a coordination failure. Chapter 4: A debt game with correlated information This chapter models of debt roll-over where a continuum of investors receives correlated signals on whether a debtor is solvent or insolvent. The investors face a collective action problem: a sufficient proportion of investors must agree to participate in the debt roll-over for it to be a success. If an insufficient proportion of investors participates in the deal, the debtor will default. The game has a unique switching strategy, which results in global uncertainty being preserved. The ex ante distribution of play (conditional on the true solvency of the debtor) follows a Vasicek credit distribution. The ex ante probability of a debt crisis is affected by the exogenous model parameters. Of particular interest is the observation that increasing private noise unambiguously reduces the probability of a debt crisis. Unsurprisingly, increasing the fiscal space or return on debt also decreases the probability of a crisis. Chapter 5: Bailouts and politics The final chapter examines the political-economic equilibrium in a two-period model with overlapping generations and a financial sector, which is inspired by the model in Tabellini (1989). The public policy is chosen under majority rule by the agents currently alive. It demonstrates that the bailout policy adopted in the second period has important effects on the bank's financing decisions in the first period. By adopting a riskier financing regime (i.e. higher leverage) in the first period, the older generation can extract consumption from the younger generation in the second period. Sovereign backstops of the financial sector are state-contingent: they can appear costless for long periods of time but eventually result in a socialization of private-sector debt. It is this mechanism that makes implementing capital requirements costly to investors yet beneficial to the younger generation. The model also highlights two important issues: (i) bank capital is endogenous and (ii) proposed resolution mechanisms must be politically credible. It suggests that a major benefit of increasing and narrowing equity-capital requirements or increasing liquidity ratios is that they are implemented ex ante and therefore available either to absorb losses in the event of a crisis or to reduce the possibility of large drops in asset values. Finally, this chapter also provides a structure by which to interpret the stylized facts of Calomiris et al. (2014): that more populist political institutions are associated with more fragile financial systems
Conservation implications of recent advances in biodiversity–functioning research
No full textStudies have shown that increasing diversity has a positive influence on many ecosystem functions and services, for example, biomass productivity. However, most diversity–functioning studies have derived their conclusions (1) from considering only random species assemblages, (2) from small spatial scales – often micro- and mesocosm experiments, (3) from studying merely a single trophic level, and (4) studies from a small number of biomes dominate. Critics argue that these studies provide little basis to evaluate the consequences for biodiversity loss in the real world. Here we re-consider the latest research focusing on each limitation in turn to highlight the possible lessons for real-world conservation from recent biodiversity–ecosystem function (BEF) research. Tentative general lessons from recent research include: (1) the need to urgently forestall human-induced extinction (i.e., non-random extinction) over large areas, in order to avert large negative functional consequences which may be more pronounced at larger scales and (2) preserve relatively intact communities because biotic interactions across the multi-trophic levels may have a synergistic contribution to the overall functioning of a system. However, considering the complexity of the community dynamics of natural systems, we recommend using natural systems – and understanding the basic physiological features and ecological roles of the species within them – because they implicitly include realistic extinction process, trophic structures and spatial–temporal scales as a useful way of increasing the relevance of future BEF studies to conservation
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
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
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
- …
